Saturday 28 May 2011

Impressive Barcelona

At 2.36, the Over 2.5 goals price seemed generous for the Champion's League Final. Lacking confidence in the spreadsheet's pricing ability on neutral games and inter-league games, I didn't play this pre-game though. Reading in-play football matches is not something that I seem to be very good at, or at least there are many out there who are better than me, but occasionally I get something right. There looked like goals from the start, and the market agreed as the prices didn't drop too fast, even with no goals until the 27'. At 2-1 to Barcelona, it appeared to me that there were still more goals to come and I switched to the 3.5 goal market for a nice profit.

I have a few bets for the French finale tomorrow, and that will be it for the season. Two Strong Draws in the Monaco v Olympique Lyonnais and Paris St Germain v St Etienne games, and value for Valenciennes (2.02), Lorient (2.66) and Lille (1.88).

I'll be back on Thursday after a few days away, sans PC, and will post up the final Strong Draw 2011 results. I know you can't wait.

Friday 27 May 2011

Hurrah For Greed

One of my finer moments this morning when a sizeable lay of the Chicago Bulls at 1.02 was snapped up by someone eager to buy some money. The price dropped even lower, before the Miami Heat staged a recovery to win from some 13 points down and for once I rode the wave all the way. Well, most of the way. I made sure that I wouldn't end up with nothing once the price started moving out. It seems that when I'm lopsided on my outcomes, the luck never goes my way. If I need a three-pointer for a big win, the shot rims out. If I need a three-pointer to stay out, the shot sails through "from downtown". Or it's a two "and one" that spoils the day, but not today. Unfortunately the PC now returns after a two month hiatus, which will get June off to a bad start seeing as the next Wednesday falls on the 1st.

Love 'em or hate 'em, we probably all have an opinion on 1.01 (or close) backers. When a 1.01 is turned over, or 'gubbed' to use the forum phrase, threads spring up pointing out how much was matched, and usually from people not involved in the carnage / ecstasy.

While my lay was at 1.02 rather than 1.01, Scott Ferguson's post titled "the money buyers get burned again hurrah, hurrah...." on the topic of laying / backing at low prices drew an interesting comment. A George commented that

I have been following the blog for about 1 year now and I have seen a few posts about 1.01-backers getting burned or having to go through a gut-wrenching reversal before getting their cent. I find all those examples interesting and have two questions. First, why are you so negative on these backers e.g. "hurrah, hurrah"? Second, by only showing the spectacular losses and never pointing out the frequent, boring wins you are not giving a fair (RoC) treatment of the strategy? I believe that it can be very profitable when paying attention to the right factors (like investment grade credit investing) and a good psychological fit for a certain type of people. Thanks.
As Scott points out in his reply, backing at 1.01 leaves little room for manouvre. The reward of laying is huge, while the risk is small, but as with any price, some 1.01s are value backs, and others are value lays. In some quieter markets, you can sometimes find 1.01 available on a completed event - now that is buying money, but in sports like NFL and basketball, the 1.01 seems to get matched too soon quite often. Scott's reply in full:
That's fair comment. The 'hurrah, hurrah' part actually related to a song I'd been listening to this morning, an old song by The Jam, so it follows the tune. But yes I do cheer when 1.01s get beaten.

Surely 'frequent, boring wins' can be achieved with far less risk by trading one tick briefly at a much higher price? Just one going wrong in 101 markets and all you can do is break square at best. Betting circles over the years have been littered with leviathan punters who took the short odds for huge sums with win after win after win.... then it all went pear-shaped and they ended up selling used cars or the Big Issue.

In the States, they call them Bridge Jumpers (where they'll end up if it loses). In Australia, we call them bank teller bets - when a horse called Ajax in the 1930s would run, it was so good it would start very long odds-on. Bank tellers would take all the cash out of their drawer on a Friday night, take it to the racetrack, take home the 'interest' and put the money back in the drawer on Monday morning. When Ajax got beaten one day at 1-40, the brown stuff hit the fan.

No doubt there is someone who can make it work but the cost of just one mistake is just far too high. At least if you were backing 1.02 shots on Betfair, there'd be an upside you could cash in on (lay 1.01) without sweating a result. Backing 1.01 leaves nothing to chance.

I'm an 'educate the masses' guy. There will always be an exception to my advice but I'm trying to stop people falling into traps (eg thinking 1.01 always equals sure thing) and using their brains to find a strategy which suits them.
When backing at 1.01 in a binary event, you do have the possibility of backing the other side at 120 or more, but in my experience, it's not easy to get matched at those prices unless you really are giving away value.

Markets are driven by two things - greed (lay low) and fear (back high).

Wednesday 25 May 2011

Strong Draws - Bundesliga and Serie A

The Bundesliga ended with the teams ranked as shown. Bayern Munich topped the ratings, but not the league, and Borussia Moenchengladbach finished in the relegation play-off spot but a decent 11th place in the ratings.

In total, the Strong Draw system had 10 winners from 27 selections, 37.04% making the somewhat unpredictable Bundesliga at least the second best of the big five leagues in terms of strike rate. France could drop below them this weekend if I have any losing picks.

The Serie A season ended with the teams ranked as shown. In total, the Strong Draw system had 10 winners from 32 selections, 31.25% - the fourth best (if you're an optimist) or the second worst if you're a realist, of the top leagues. I'm an optimist. With an average price on the selections just shy of 3.45, 31.25% is more than enough.

The best and worst Strong Draw performing leagues will be finalised and revealed when the seasons end for the English, French and Spanish teams.

Tuesday 24 May 2011

I-O, Compare, Win

Imagine a game played with two coins. One head / one tail is a home win. Two heads is a draw, and two tails is an away win. To price up a match precisely would be rather easy, but when it comes to football, it’s a little trickier.

As I mentioned a couple of posts ago, mano said in a comment:

You mentioned in an earlier post that you have configured your Elo spreadsheet so that it can give you a goal expectation for each team in a forthcoming game. I maintain Elo ratings myself for a few leagues, and was wondering how you managed this. I don't expect you necessarily to reveal your workings and endanger your edge, but would you be able at all to point me at least in the right direction?
When I first started rating teams, I thought I would be able to plug in the two numbers and have a magic formula spit out some prices for me, but that didn't work.

What did prove to be more successful was taking the next step towards calculating the result needed to maintain a team's rating, and this is the strategy used to generate the Strong Draw picks that have proved so successful, but when it comes to generating prices, it finally dawned on me that the starting point has to be the number of goals each team is expected to score.

Once you have these two numbers, it is relatively easy to use Excel and the POISSON function to generate the probability that each team will score exactly 0, 1, 2, 3… goals. And from there it’s simple enough to calculate the probability of any correct score, match odds or over / under outcome. If both teams have a probability of 0.25 of scoring zero goals, then we can price up the 0-0 score at 16.0. Repeat this exercise for all the Under 2.5 results, add them together, and you have a price for that market. Add up all the home results and you have the Match Odds home price and so on.

It’s easier said than done of course, because you first have to come up with the number of goals a team might be expected to score. I use a team's previous games, both home and away, with any 'extreme' results smoothed out.

As might be expected, recent results carry the most weight, but it's more than just the result goes into generating this number. I look at the shots, shots-on-goal, and corners numbers too, as well as the relative strength of the opponents in each game. This is where the Elo ratings come in. Since each team has a rating, a ‘performance’ worth 1.5 versus a highly rated team might be worth 2.0 versus a bottom of the table team. A goal at Manchester United is given more value than a goal at home to Blackpool, and a 4-0 win is significantly devalued if the team ‘lost’ on shots, shots-on-goal and corners.

The end result of all these inputs is one number per team per game – the estimated number of goals that team will score against their opposition. Again, this number will vary depending on the strength of the opposition for obvious reasons.

The numbers are also time-sensitive because ratings are constantly changing,

In the same way that the ‘average’ UK family used to have an impossible 2.4 kids (now down to an equally impossible 1.9 I believe), the probable number of goals a team will score is unlikely to be an integer, but we can still use this fractional number as input to the POISSON function.

From Wikipedia
The first model predicting outcomes of football matches between teams with different skills was proposed by Maher in 1982. According to his model, the goals, which the opponents score during the game, are drawn from the Poisson distribution.
While the Poisson distribution arguably doesn’t work well for ‘binary’ scores (0-0, 0-1, 1-0 and 1-1), by factoring in more than just goals scored, the model seems to work reasonably enough. Besides, I remember Poisson from my Pure Mathematics With Statistics 'A' Level, whereas my recollection, knowledge and understanding of Binomial distribution are pretty much non-existent. No, that's a lie. They are non-existent.

Early observations are that my draw prices do tend to come in on the high side, possibly the result of my model underestimating these ‘binary’ scores, which contain two of the most common draw results, but a couple of statisticians, Mark J. Dixon and Stuart Coles, (authors of the 1997 paper Association Football Scores and Inefficiencies in the Football Betting Market), invented a correlation factor to compensate for these low scores, and I may have to reinvent something similar.

The maths can get complicated, but if I am finding value in the 0-0, either backing or laying, in every game, then clearly an adjustment is needed, and I have no qualms about tweaking.

I’ve been saying that this spreadsheet is a work in progress for a while now, but I do feel that there is finally light at the end of the tunnel. Of course, it could be a train, and while 31 games at the end of a season is a very small sample, a profit on the Match Odds markets of 14.43 points from 26 markets where value was identified, is a good start.

The Under / Over 2.5 selections were a little more, well, selective, generating 5.75 points from 14 qualifying matches.

Roll on 2011-12.

Sunday 22 May 2011

Recency Effect

It is certainly true that the final round of the EPL today makes for a dramatic finish in the relegation battle, but the claim that today "undoubtedly is the most intriguing end of season relegation battle in the history of the English Premier League" shows how selective and short our memories can be.

The reality is that undoubtedly it is NOT the most intriguing end of season relegation battle in the history of the English Premier League at all.

Cast your minds back a mere six years, when the final day of the 2004-05 season arrived with not one team definitely relegated from the EPL. It was the first time since 1992-93 that this had happened since three-up, three-down was introduced as West Bromwich Albion, Norwich City, Crystal Palace and Southampton all tried to avoid the drop.

I'll let Wikipedia explain it all:

Going into the final round of matches, no team was assured of relegation. In each of the last three weekends of the season, the team that was bottom of the table at the start of the weekend finished it outside the drop zone. The final round of the season on 15 May started with West Bromwich Albion on the bottom, Southampton and Crystal Palace one point clear, and Norwich City in the last safe spot and two points from the bottom. For the first time since the advent of the current Premier League in 1992–1993, no club was assured of relegation going into the final day. The final matchday was publicised by Sky Sports as 'Survival Sunday', with accompanying promotional material advertising the last matchday like a title fight or epic movie blockbuster.

West Brom, who had been bottom of the table and eight points from safety at Christmas, did their part by defeating Portsmouth at home 2–0. Norwich, the only side to have their fate completely in their own hands, lost 6–0 at Fulham and went down. Southampton lost 2–1 at home to Manchester United. Palace, away to Charlton, were leading 2–1 after 71 minutes, but with eight minutes to go, the Addicks' Jonathan Fortune equalised to relegate the Eagles back to The Championship. Thus, West Brom stayed up, and changed history, becoming the first club in Premiership history to avoid relegation after being bottom of the table at Christmas.
One should never say never, but the drama of that 'never' to be forgotten (15.5.05) day will 'never' be beaten.

Rapture For AFC Wimbledon

I have the draw priced at 3.23, but perhaps Udinese v AC Milan should be added to the Strong Draw Picks based on their current price of 1.72. The draw has traded as low as 1.5 and no higher then 2.28 so clearly the usual rules do not apply. Udinese need just a point to advance through the "gates of paradise" (as coach Francesco Guidolin puts it) and seal the fourth Champions League spot, and one imagines that AC Milan won't be too concerned about winning. The two teams drew 4-4 in Milan. It's a huge opportunity for provincial Udinese, since qualifying for the Champions League will be a lot harder from next season, now that the Bundesliga has overtaken Serie A in UEFA’s table of coefficients.

Other than this game, with the relegation issues already settled, none are meaningful and probably not a good week to do much other than back the draw at Brescia and lay a few favourites for small stakes.

Spain wrapped up their domestic season yesterday, with Deportivo La Coruna being relegated after 20 seasons at the top. They wouldn't have been relegated if these things were decided on my Elo ratings, since they finished in a relatively decent 13th place, and it would have been Real Sociedad taking the drop with Almeria and Hercules, who finished the Spanish Strong Draw picks for this season with a 0-0 at a tasty 3.8.

A little over two years ago, I wrote

What price on AFC Wimbledon topping this league next season? I have to say that when the club was formed I thought the whole enterprise was doomed to failure, but in less than seven years the club are now just one step away from the Football League and playing the likes of former top division teams Luton Town and Oxford United. That is a great story.
The great story is even greater now as AFC Wimbledon win a deserved place in the Football League next season. (I say deserved in reference to the fact that they finished clear in second place, six points ahead of Luton Town, in the regular season).

Say of them what you will, but play-offs make for dramatic finales to a season. Luton should be back next season, but I suspect most neutral fans were behind Wimbledon yesterday.

Five promotions in eight seasons after starting their competitive life with a 1-2 loss against Chipstead in 2002 in front of 4,215 fans, is quite impressive, and only once have they failed to improve upon their previous season's finishing position.

The full-time Chief Executive's salary? - He receives the nominal sum of one guinea a year, because "it sounded posher than a pound".

Saturday 21 May 2011

How Not To Win

While in-play baseball has nothing like the liquidity of basketball, there are often games at a decent hour on weekends or getaway days, and the occasional opportunity. This weekend sees some inter-league games, and the American League teams have come out ahead in each of the last seven seasons. The Chicago White Sox have the second best record in these games, and at home to the National League's Los Angeles Dodgers were attractive at 2.0 today.

As is my wont, I had my in-play lay in at a low, but best available, 1.02, and with the score 1-0 to the White Sox, I was a little surprised to see £10 taken at this price - in the middle of the second innings! Eh? The probability of a team leading by 1 run at this stage going on to win the game is 65.4% (1.53) and 1.02 is a little greater than that at 98%.

At the time of writing, the fourth inning has just ended and the White Sox are up by 7-1 so the backer may well get away with it, but backing at 1.02 in one run games with 5/6 of the game still to go is not a long-term winning strategy.

I await O'Dwyers next screenshot with interest, as I suspect my 20p may be found on his baseball statement.

Incidentally, I have £275 currently sitting at 1.02 if anyone is interested. The correct price for a team leading by 4 at this stage of the game is 1.08, and while "The Book" doesn't list the probabilities for a bigger lead than four, 1.02 seems about right. Help yourselves - I don't care. The world could end at any moment.

Friday 20 May 2011

Final Day

When I was a youngster, the football season seemed to last for ever, but these days, they're over in a flash. This weekend sees the final games in the EPL, and the screenshot above contains my selections. I'm also finding value in the Over 2.5 goal markets in the games at Fulham, West Ham United and Wolverhampton Wanderers.

I had a comment on the last post:

You mentioned in an earlier post that you have configured your Elo spreadsheet so that it can give you a goal expectation for each team in a forthcoming game. I maintain Elo ratings myself for a few leagues, and was wondering how you managed this. I don't expect you necessarily to reveal your workings and endanger your edge, but would you be able at all to point me at least in the right direction?
which I will address in the near future. I don't think my edge will be endangered too much. I've not noticed the price crashing on too many of my published selections.

Sunday 15 May 2011

EPL Penultimate Round

Mixed results this weekend. The Strong Draw system (I really must find a catchier name for next season) went 1 for 5, showing a loss on the weekend of 1.6 points, with the ROI in 2011 now at 13.57%, while the EPL Value spreadsheet had a poor Saturday but a great Sunday, finding winners today in lays of Arsenal and Chelsea, as well as backs of Fulham and Wigan Athletic at prices of 3.38, 4.7, 3.6 and 2.26 respectively.

Overall on the weekend, the Match Odds returned a profit of 8.18 points from 8 selections, while the Under / Over selections were up slightly, by 0.03 points with two winners from four selections.

It's hard to get too excited about results from games at this time of year given that matches are not necessarily being contested as they would have been earlier in the season, but the results are promising.

Perhaps a little fortunate today with late goals from Olympique Marseille, Newcastle United and Wigan Athletic, but it feels like I am owed a few of those.

A good weekend too for laying the EPL favourites, with only Wigan Athletic victorious out of nine selections, and odds-on non-winners in Manchester United, Arsenal, Chelsea and Liverpool.

Insanity Laughs

...under pressure, we're cracking. Can't we give ourselves one more chance?

The quotation "The definition of insanity is continuing to do the same thing over and over, and then expecting different results" is usually attributed to Albert Einstein, although Rita Mae Brown may actually deserve the credit, but it's a good quote.

I was reminded of it while replying to a comment by our old friend John O'Dwyer who mentioned in a recent post that in the recent Snooker World Championship, he had noticed

This is only one of the differences I've found compared to previous years. A bit like the Darts, someone out there is beating the Betfair clock by a good few seconds.
This is the main reason that I don't like betting on tennis in-running. With court-siders in attendance, what is the point? Any bets that you get matched are unlikely to be value, and we all know, or should know, that without value we will lose long-term. Betting between games might be a viable option, but in-game point to point betting when someone is a few seconds ahead of you is, in my opinion, a waste of time.

John, like many insecure men, is obsessed with size - although in his case it is with bank size. He wrote yesterday
I'll probably do another update tomorrow, but I'm getting tired and fed up. It's been another struggling week. I'm using a small bank, and I'm trying to rush things and it's continuously going wrong. One of these days I might get to 1k again, and it will progress from there. I was saying this exact same thing in Jan 2010, before doing exactly what I expected to do once I got the bank size I kept going on about. Until then, I am beat. I owe so much that getting a normal job will not get me out of the trouble I am in. I've known the answer to the problem for months, but have not been able to resolve it due to a few reasons.
My advice:
John - your mind needs to be clear to be successful as a trader. "Scared money don't win". Bank size isn't an issue. Like I said to you before, if you have an edge, you can start at any level and soon build a bank. I started with less than £100 and have never made a second deposit. What qualifications do you have? My advice is to get a 'normal' job and trade any edge you can develop part-time. But you need to find an edge rather than use your current approach which you may have got lucky with for a while, but luck has a habit of running out.
But there's no helping some people.
Remember, this is me being honest whether I win or lose. It's all factual from me. A lot of people have opinions on why I've lost, but at the end of the day, what credentials do they have?! Where is the proof of their wins, to back up their assumptions that I am wrong in what I say? I know I am right, that's the thing. I don't need people telling me it's nothing to do with a bank size, espcially when people are guessing themselves with nothing to back up what they say.
The point is that he is not accepting reality.
No one is doubting your honesty, but do you understand that no one who makes a profit from betting long-term does so without having an edge? You can take or leave any advice you are given, that is your choice, and while there are certainly people who offer advice who probably shouldn't, there are also people who are profitable long-term, and are in a position to offer sound advice based on their experience.

The reason you lose is quite simply because you do not have an edge. You can, and did, get away with this for a while but you can't defy the odds long-term. It is not unusual to walk away from a table in Las Vegas with a decent profit on a single night, but if you went there every night, you would lose. The odds are against you. You can back 1.05 shots all day and have long winning runs, but if the true price is 1.06 (or more) you will ultimately lose.

In the first 9 days of May, you bet on baseball, basketball, boxing, cricket, horse-racing, golf, snooker, soccer, tennis, aussie rules, rugby league and rugby union. Are you seriously claiming that you have an edge in all those events? That someone in Barnstaple, North Devon, has identified an edge that has been missed by everybody else?

There's nothing wrong per se with betting on any of these events, but in my opinion you need to specialise.

And if you notice that someone is beating the clock in snooker as you mentioned a few days ago, walk away. Any bets you get matched are unlikely to be value, and it is insane to stay in a market where someone has an edge over you. Nothing will stop court-siders faster than no money in the market.
But all advice falls on deaf ears it seems.

Having completed the above, I notice a late comment from John, which just proves further that he doesn't know what an edge is.
I do have a edge, but it all revolves around having a bigger bank size. That's why I've been losing recently. Big bank brings stability, which I've always said.

I've not had 2k in my account since January, so there has been no way for me to back up what I say.
If you go to Gold All Over, you will see my EPL Value spreadsheet which shows the edge I believe I have, (or don't have), on recent EPL games. Edge is simply (StrikeRate * Probability of Winning) - ((1 * StrikeRate * Probability of Losing). If your edge is negative, as it will be for a game such as Roulette, then long-term, your expectation is negative.

But the key here is that the edge does not change depending on your bank size.

Saturday 14 May 2011

Harvest And Blue Moons

My spreadsheet doesn't handle neutral venues very well, so the FA Cup Final for once takes a back-seat to the League action, which is unfortunate really. Cup Final day was always a highlight of my year, and one of the earliest I can remember was another "all City" final - the one between Manchester and Leicester in 1969. City in their red and black stripes, Leicester in blue, but for me it was all in black and white. I am the victim of a deprived childhood. Life-long City fan Neil Young scored the winner, and Big Mal, a hero of mine in later years, had his hands on another major trophy.

The overriding memory of that year was the excitement about Crystal Palace taking their rightful place in the top division for the first time in their history, a summer holiday in North Devon that I recall being blessed with sunshine every day, although looking back, that seems a little unlikely, and watching another Neil go for a walk on the Moon.

Bryan Adams had a good summer that year too.

Coincidentally, Manchester City beat Leicester City in the Third Round this year, with Roberto Mancini wearing a red and black scarf that day in a tribute to cancer stricken Neil Young who sadly passed away soon after in February this year aged just 66. Most readers of this blog are probably much younger than I am, and think that 66 is a decent age, but the older you get, the younger it seems.

It's also perhaps worth pointing out that few players in those days made enough money to see them through life after football. Not helped perhaps by two divorces, Young had many different jobs, including removals, managing a sports shop, delivering milk, working in a supermarket and selling insurance. His financial problems meant he had to move in with his mother. "Deeply depressed at this point in his life, at one point he attempted suicide". While the thought of moving back in with my mother would certainly be a little depressing, I'm not sure that I would go so far as to commit suicide to avoid it. Well, OK, maybe I would.

On to more serious matters than death, cancer and suicide and what do we have in store so far as the league action is concerned today? Some strong draws in Blackpool v Bolton Wanderers, West Bromwich Albion v Everton (the 1968 Cup Final teams), and Freiburg v Bayer Leverkusen. These, and more, are posted over at Gold All Over. Keen eyes will notice that I missed out on three picks in midweek, simply because it takes me so long to catch up the numbers these days that I was simply too slow. As is often the case with these things, two of the the three went on to win. Typical, and I still need to catch up France, Spain and Germany.

The Value spreadsheet shows nothing in the Over / Under market of value for the EPL games, but Bolton, Sunderland and Everton all look value (in that order), as do Blackburn, although the lay of United will be my play here.

Serie A has now joined the EPL in having all the data caught up, and Unders looks to be the value in both games. What is very strange is that in the AC Milan v Cagliari game, my Match Odds are exactly those on the exchange, yet my Under / Over 2.5 goals prices are reversed. While I have the Under at 1.7, on Betfair it is available at 2.62! This is a dangerous game though, with the title already clinched, the game is unlikely to played in the same manner as it would have been a few weeks ago.

The Lazio v Genoa game is the same with the Under / Over flip-flopped, although my Match Odds are a little different, with a lay of Lazio the value bet.

Lest any readers take me too seriously, my Mum does not read this blog. Tech savvy she is not - in fact, the first Cup Final she saw in colour was Chelsea v Portsmouth last year - she was waiting for the prices to come down - not counting the Manchester City v Bolton Wanderers final, which she saw in person at the Crystal Palace. Maybe.

Tuesday 10 May 2011

Double Chance?

Gold All Over has it's first (non-spam) comment which means at least one person is taking a look at my screen-shots over there! The Football Analyst recently concluded that the DC (Double Chance) wasn't for him, and I need to decide how to play the longer priced selections that the Poisson Value system highlights. Keith's comment was:

Wow that really is a piece of work - looks great!!

How do you decide whether to lay or back the value selection? e.g Stoke v Arsenal - Stoke had a home edge of 91% but in your selection you had layed Arsenal whereas Everton v Man City - everton had 58.7 home edge and in selection you had backed Everton for win - is it a judgement call? Or probably I may be missing something!!!!

Enjoy following you on here and over at "Green All Over"
The answer is that I quite arbitrarily picked odds of 4.0 as the deciding line between backing the selection outright of getting the draw on my side. So for example on Saturday, Everton were backed at 3.0 v Manchester City whereas for Stoke City at 5.5 on Sunday, I went with the lay of Arsenal. After a larger sample than 11, I shall revisit this, but, as I said in my reply, I don't like my losing runs to be too long!

It's a promising start for this system at a tricky time of the season, and it's a little unfortunate that I didn't get all the parameters in place earlier, but at least it is ready to go for 2011-12.

Saturday 7 May 2011


I've had worse days. AS Roma's draw with AC Milan at 3.5 and Everton's come from behind defeat of Manchester City were probably the highlights, on a day when every EPL team scored either one goal or two.

Everton's win was also tipped up by Football Elite (Draw No Bet) but they had a loser with Sporting Gijon.

Every single EPL Over / Under favourite lost, giving me three winners at 2.06, 2.03 and 2.14 from five selections. With the spreadsheet now using goal scoring probability to calculate match odds, it also gives me prices on the peripheral markets such as the Correct Score and the Over / Unders. The biggest value on Over was Newcastle v Birmingham which I had priced at 1.6, yet 2.14 was available. 2.03 was available for Overs at Bolton, a game I had priced at 1.65. West Ham v Blackburn wasn't so good - I had Over's here at 1.46 and available at 1.85, but we're not going to win them all. The prices on the Tottenham Hotspur v Blackpool game were almost exactly as I had - 3.15 available on Under where I had 3.17.

The excellent Soccermetrics blog has a post today which covers the subject of how to weight the data used to calculate a team's goal-scoring probability. I do this myself, since it seems to me that a goal at Chelsea should count for more than a goal at home to Blackpool, and similarly shots, shots on target and corners should be adjusted similarly. The weighting I use is based on the teams Elo based ratings, but Soccermetrics suggests using "the league position of the opposing team at the time of the match". He goes on to say that

I use a somewhat more sophisticated function. The rationale is the same -- goals scored against the top teams in the league should count more than goals scored against the cellar-dwellers. Or to put it another way, goals scored against lower-ranked teams are worth less than those scored against higher-ranked teams, and goals scored against the top team in the league (at that time) should count most of all.
No argument there, but I find the use of league positions rather simplistic and somewhat flawed. I left a comment which included:
The method I use is to rate teams using an Elo based rating system. This takes into account the strength of the opponent so that for example a 0-1 loss at Chelsea doesn't impact a rating so much as a 0-4 defeat at home to Blackpool. There are problems with simply using league position. Some are 1) Early in the season, these often are very misleading. 2) Games played do not always remain in sync. 3) A couple of points can separate several teams. 4) Conversely, a team can be well clear, or well adrift, but they are treated the same as if they were ahead, or adrift, on goal difference.
Soccermetrics has a far greater understanding of statistics than I could ever claim, so incorporating this idea into his calculations should be no problem.

For anyone interested, the Under / Over value tomorrow and Monday in the EPL looks to be on the Overs. I have Wolves v WBA at 1.58, with 1.89 available. Stoke City v Arsenal 1.63 and 1.91 respectively. Manchester United v Chelsea 1.93, 2.23 and Fulham v Liverpool 2.11, 2.23.

Early Bird

It's too late for this season, but I have finally adapted the Elo based ratings spreadsheet to generate, for the most part, reasonable odds for the EPL. The other leagues will need a few more hours of work which will probably be found in the close season. So for now, it's all eyes on the EPL, and a few games I priced up on Thursday morning have significantly shortened since.

Bolton Wanderers were at 1.89 to beat Sunderland, but they are now down to 1.78. I have them priced at 1.74, so the value is gone.

Everton were at 3.0 to beat Manchester City, now down to 2.78. I have them priced at (don't laugh) 1.89 for this game. Everton really aren't that bad, and ranked 6th are rated just behind Manchester City in 5th. Their league position is a little false in my opinion, and 3.0 or anything close represents excellent value.

Newcastle were at 1.99 to beat Birmingham, now down slightly to 1.93, still over my price of 1.74.

Fulham remain at 3.1 to beat Liverpool, value with my odds for Fulham at 2.37, and finally, I have Arsenal priced at 2.43 to win at Stoke, where a lay at 1.75 looks good value.

Being silly season, we shouldn't get too carried away though, and Arsenal, Bolton and Newcastle both qualify for the 'lay-the-favourite' system which has been well researched and reported on by Green Eyed Trader. Manchester City's upcoming FA Cup Final appearance may reduce their focus at Everton, and will Newcastle be too disappointed with just a point versus Birmingham?

It might be worth bringing forward my weekly research by a day or two. With three of the four picks shortening significantly, I could be on to something, but I won't know for sure until I have 100,000 results in my records!

Two strong draws posted over at Gold All Over - both in Serie A, AS Roma v AC Milan (3.5) and Lecce v Napoli (3.7).

Pete Nordsted goes for draws in the Newcastle United v Birmingham City, Stoke City v Arsenal and Fulham v Liverpool matches.

Wednesday 4 May 2011

Cornering The Market

Long-time readers will know that the Elo based rating spreadsheet has steadily evolved since it's inception, and currently uses shots, shots-on-target and corners as factors in rating a team's performance in addition to goals, which taken alone can produce a distorted view of a match.

For example, on 20 December 2010, Manchester City played Everton.

Shots - Manchester City 25, Everton 4.
Shots-on-Target - Manchester City 15 Everton 3.
Corners - Manchester City 11 Everton 0.

Result: Manchester City 1 Everton 2.

The result here is not an accurate reflection of the match, but what would be? The Reep ratio (one goal:nine shots) has stood the test of time, but for weighting the value of corners I used my own research. It is conventional wisdom that corners lead to goals, but as Moneyball and Soccernomics both showed, conventional wisdom isn't always right.

A fascinating post from Soccer By The Numbers concludes that the value of corners is overrated. "Turns out that more corners don't equal more goals".

I use corners as a factor in rating weighting (very poetic) not as a tool for predicting goals, but it did occur to me that perhaps the in-play markets overreact to the award of a corner. If the finding that the "yield from corners ranges from 0 to .07" in the EPL is correct, and the blog is meticulously written, so I have every confidence in its findings, when the price in a market drops by three ticks for a corner, there should be value in opposing this move. Corners are not the goal scoring opportunities they are generally considered to be, but still strike terror into the hearts of traders hoping the status quo will be maintained, and gladden the hearts of traders betting on a change.

Measuring Weakness

The consensus among traders is that a sub-category under the heading of "Discipline" is that of keeping accurate records, but it is arguable this may be more of a hindrance than a help at times. The previously discussed Dr. J thread had a comment to this effect

The worst thing about keeping note of good betting runs is that we are setting up artificial hurdles for ourselves. We are creating a difficulty that should not exist.
As an illustration, as April was winding down, I was very much aware of how close to ridding my spreadsheet of the one red month I was. While I tried not to let this affect my betting, the seed was planted in the back of my mind, and undoubtedly impacted my decision making process. I had the short-term goal of making a large enough profit in April to cover previous losses, which meant that I was more selective than I would normally be.

While it could be argued that this target was meaningless and artificial, to me it was important. Passing any milestone is really meaningless, but going from say £980 to £1,001 is probably more exciting to most people than going from £1,001 to £1,023, even if the latter is the bigger win.

How would I have bet if April had been close to a record month, and I needed 'just' another £300 on the 30th to beat my personal best? Would my betting have been a little looser than normal in an attempt to beat that artificial goal? While we should always play the same way, I doubt that too many of us have completely mastered this skill.

One suggestion on the Betfair Forum from a few years ago, was to trade without your balance or P&L figure showing on the screen - the idea being of course that your decisions would be based on the current situation alone, uninfluenced by factors such as those I have mentioned above. Easier said than done, but the idea does have some merit.

There was another comment that was mildly amusing, given that the thread starter has made close to £200k in seven years. After reporting that recent results had been poor, someone posted this gem
...but I now see a real weakness - and maybe you have to convince that your edge has been tested sufficiently over enough events
OK, poor English, but you get the idea. The number of events that the commenter felt was required to prove an edge exists? Here's his answer
I know we are digressing from the main theme of the OP [Original Poster], but to me the 'edge' has to be proven over at least 100,000 events before you can claim it being successful.
100,000! Talk about an artificial number. 99,000 won't do, but roll that odometer over to six digits, and now we're on to something real!

One reply, which I thought was particularly brilliant, was:
Any edge in the markets only exists because there is an inefficiency, and will not last forever. The edge may be 'proven' one day, and 'proven' to be gone the next day. However, in markets, as in plate tectonics, as one edge closes, another one may open. 100,000 trials in the context of sports betting is nuts. At 20 bets a day, it would be close to 14 years before you had that number of bets, and to say that the markets might have changed in that time would be putting it mildly. And if you have a system that produces 20 value bets a day, you should be living in the Cayman Islands long before 14 years has passed by applying Kelly.
At the rate my Strong Draws are showing up, it'll be 645 years before I know if I have an edge or not. The Methuselah Foundation had better get moving.

Tuesday 3 May 2011

Intellectual Hobby

Lazy Trader (though I'm sure he's not) said

Just read the Dr J thread, thought you were opposed to those dick waving profit type threads :)
It is true that I don't see the value of blog posts or threads that simply give a regular P&L update, but the post from Dr J wasn't of this type. He had reached the milestone of £200k (although he has slipped back below this number since posting) which to my mind at least is certainly an achievement, and to mark the occasion, he wrote, in my opinion at least, a post that came across as honest, humble and inspirational as well as offering advice on how success can be achieved.

Lazy Trader continued:
Think the thing it highlighted for me was the difference between being a part timer and full timer of which I've been both. Part time, especially with a decent enough paid job, it's very much an intellectual type hobby where you're happy to pits your wits against the best and the rewards are secondary. Full time it's simply about money and you'd rather be pitting your wits against the worst players.

My situation was pretty much similar to Talkbets where I was self employed able to take time off now and then to play. It was only when circumstances changed and I went full time I really stepped up a gear mainly because I needed to.
I think the key here is the statement "it was only when circumstances changed..." In what way did circumstances change? If your full-time job comes to an end for reasons beyond your control, or the bottom falls out of the contracting market (as it tends to do from time to time), then that's one thing. If you've had success on the exchanges as a part-timer, then that option is certainly a viable one, but that's quite different to voluntarily giving up a "decent enough paid job" to trade on the exchanges. That enjoyable "intellectual type hobby" would soon become a high pressure job.

As for "stepping up a gear", it's reasonable to assume that if you can make a certain amount part-time, that you could increase that amount at least somewhat, but I seriously doubt that I could ever increase it by enough to cover the lost income and more importantly the investment in your future income that a decent job gives you. I already cherry-pick my strongest markets as a part-timer, and going full-time would only mean more time available for sports that I'm not very good in. Could I improve in these? Almost certainly. Could I improve enough to justify going full-time? I'm not so sure on that question.

While there are many full-timers around, there are not many who appear to have given up decent careers for it.

No Respect

I'm not sure that the posting of a monthly update is of much interest to anyone but the blogger himself, but for the record, the month of April is now overall in profit, with a less than impressive daily average over the six years of £1.68. But it's a profit, and with every other calendar month well in profit, there will, barring disaster, be no red in the Monthly Summary update for at least another year. Taking a break for a couple of weeks seems to be the way to go!

Another award came my way yesterday, although I suspect the judges at Full Time Betting weren't being entirely serious. If only these awards came with a cash prize as does the Nobel Prize. Once again, the world of Sports Investment Research is treated with less respect than the goings on at CERN. Our understanding of the universe might be about to change, but how will the Lakers react to losing Game 1 at home to the Dallas Mavericks is probably a slightly more interesting question for most readers.

I have had one request, well actually I offered, for an e-mail giving my Strong Draw selections. It's late in the season, but if anyone is interested for next season just let me know. At the end of the season, I'll publish the numbers, but for the second consecutive year, it seems that in certain matches, the draw offers better value than betting on the home or away team. An article on discussed Pete Nordsted's Drawmaster system earlier this season,with a bookie suggesting that

There are a couple of aspects to this theory that make it more appealing than an evening at Hugh Hefner’s grotto. The main aspect is the value that is available in backing the draw. People tend to bet with their ‘gut’, following their instincts and often backing the team they would like to win.

This means that a bookmaker’s liabilities can be stacked up on either team but only paltry amounts end up being staked on the draw. How does this help I hear you ask? Well if no one is backing a particular occurrence, the bookmaker will raise the price and in turn beef up Peter’s profit margin when a winner is selected.

If the true price of the draw is around 3.25, then the lack of bets can often boost the price to 3.5 or even 4.0. Add to that the fact that Peter’s selections often find draws in games where there is a heavy favourite to win the game and the price for the draw can be even greater still.
The average price is a little over 3.4 on my selections (in 2011), with a strike rate of 34.5% on the season. It may not be the most exciting bet to follow, but if you're serious about making money on the exchanges, you aren't looking for excitement.

Finally, the Dr J thread continues to thrive on the Betfair Forum, proving to be a thread with, for the most part, some sensible comments.

Sunday 1 May 2011

Down, But Not Out

Sad to hear that another legend from my childhood has died. While Henry Cooper's 1963 fight with Cassius Clay was a little too early for my memory, I do recall the World Heavyweight Title fight in May 1966 at Highbury against Muhammad Ali, and his final fight against Joe Bugner in 1971. Cooper's 1963 fight with Cassius Clay at Wembley Stadium is a great example of how the truth should never be allowed to get in the way of a good story. 

For those not as old as me, which is probably most readers, the unbeaten Clay was knocked down by a left-hook from Cooper in the fourth round, a blow that Ali (nee Clay) later said "had hit him so hard that his ancestors in Africa felt it". In the fifth round, the fight was stopped due to Cooper being cut, while ahead on the scorecard. That much is fact, but for years after, the claim by Cooper and his fans was that during the break between the 4th and 5th rounds, Clay was given an extra 3 to 5 minutes to recover while looking for a new pair of gloves. The tapes show that in fact the extra time was six seconds, although it is also a fact that Clay's trainer used smelling salts, which was against the rules. Even today, people will relate the story of the extra five minutes as if it were fact. It was Mark Twain who quipped that "a lie can travel halfway around the world while the truth is putting on its shoes".

Not a good weekend for the Strong Draw picks with late goals again upsetting two of the four losing picks. The ROI drops precipitously to 8.68% for the year. Pete Nordsted found Wigan Athletic v Everton to pad his profits for these bets, but Football Elite came up short with their sole pick of Deportivo La Coruna (Draw No Bet) v Atletico Madrid (0-1). This was one of my strong draws, so I guess an away win was always on the cards here!