Monday 22 January 2018

Crisco Cops

A profitable NFL Championship round yesterday, with only the New England Patriots failing to cover the spread v the Jacksonville Jaguars a loser. Unders was a winner continuing the sequence for the Patriots in this round.

In the second game, the Home Philadelphia Eagles made the +3 look silly, winning the game v the Minnesota Vikings by 31 points and an easy win for the Overs.

The Eagles win means another trip for me to that city, for Superbowl LII weekend. 

During a moderate to heavy session in the city of brotherly love last November, I recklessly promised to return should the Eagles make it to the Superbowl. 

I'm a man of my word, so I plan to be there. It should be a great experience, and the Crispo Cops will doubtless be out in force that weekend.

As I already have a work trip starting today until January 31st, it will be a while I'm home for any length of time. My wife will not be happy.

I leave you with some numbers from a system that backs the EPL Draw on a simple weighted scale of 0 to 5 points.

Since the Pinnacle Closing Era, the results of this method are:

I did also go back to the six seasons prior to Pinnacle, and using Bet365 prices and their 105%+ books, this strategy is still profitable. 

Remember that Pinnacle's prices can often be beaten, so these figures represent an 'at least' amount.

The first column shows the percentage of matches resulting in a Draw for each season, while the selections is the number of matches, and the staked column is the amount staked, between 1 and 5, although 5's are rare. Returns by staking level are here:
This past weekend's Draw selections were 3 points on the Everton v West Bromwich Albion game, and a point each on Stoke City v Huddersfield Town and West Ham United v AFC Bournemouth which resulted in a profit of 7.28 points. 

Back in February.  

Sunday 21 January 2018

Championship Weekend and More on the Draw

The Home team and Overs is the trendy play in the NFL Championship round. From the 2001 season, Home teams are 17-15 ATS (against the spread) while Overs has a 19-12-1 record.

The first game is the AFC's Championship game between the New England Patriots and the Jacksonville Jaguars. The line is currently 7 points, and of the 11 previous Championship games with a spread in the 5 - 9 point range, the home team is 7-4. When New England are hosting the game, the Unders has a 5-1 record, the one Overs being last season's rout of the Pittsburgh Steelers. While this type of team stat is generally useless, it's a little more relevant here given that the head coach (Bill Belichick) has been there since 2000, the same year current quarterback Tom Brady was drafted. 

The second game is the NFC title game between the Philadelphia Eagles and the Minnesota Vikings. The Road Vikings are favourites, giving three points, only the sixth time the road team has been favoured in a Championship game.

In 2016, the Patriots were three point favourites at Denver Broncos and lost the game.

In 2012, the San Francisco 49ers won and covered against the Atlanta Falcons when getting 3.5 points, and in 2010, the Green Bay Packers were also 3.5 point favourites at the Chicago Bears, and both won and covered.

In 2008, the Eagles were 3.5 point favourites to win at the Arizona Cardinals but lost by seven and in 2005, the Patriots were three point favourites in Pittsburgh and won by 14 points.

In the last four seasons, all eight home teams have won, and by some big margins. The average line for the home team has been 4.5 points, while the average margin of victory has been by 17.25 points.

While looking at the numbers this week, I discovered that the Week 18 for Wild Card games, Week 19 for Divisional and Week 20 for Championship wasn't actually the case in the 2001 season, which was extended by a week following the 9/11 attacks. The spreadsheet has been corrected.

I was also corrected by the esteemed Jospeh Buchdahl on my numbers for the EPL Draws for 2013-14 in my post on the EPL Draw last week. The problem was that I had resurrected a spreadsheet that only had results up to February of that season. The numbers by season are tabulated below, although the 2011-12 season was a more exclusive XX-Draws sub-set of the selections from 2012-14. Also worth mentioning that we did not have Pinnacle prices in 2011-12, so I have used those from Bet365. I've also used those for a couple of matches in Serie A where there were also no Pinnacle prices, presumably due to the Dodgy Draw in those games. 

The table shows the XXDraws by league and by season, and for comparison also the results of blindly backing the Draw (not a good idea) and of backing it in matches where neither team is odds-on, which in the EPL at least is a good starting point.

Regarding the numbers for 2013-14, this was a very poor season for Draws across the big leagues: 

Joseph's thoughts on this season were that:
This show that with other European leagues included XX Draws failed to make a profit that year. Does this not illustrate my original point about data dredging?
For me, this is not what "dredging" is about, and in the same way that a managed mutual fund will tend to go down if the indexes go down, and up in an up year, the measure of its worth is how that fund compares with a benchmark.

The benchmark in 2013-14 for Draws performed rather poorly, which isn't surprising given that compared with the previous ten years, Serie A was at its fewest ever, the EPL was at its second fewest ever, one Draw more than in 2005-06, the Bundesliga was also at its second fewest ever, one Draw more than 2010-11, La Liga was at its third fewest ever, and only in Ligue 1 were they close to average, albeit still below average.

There were 47 more draws the following season, a number repeated in 2015-16. 

To me, data dredging is more along the lines of 'discovering' a pattern in data, and trying to back-fit a system for it. For finding value in Draws, there's a logic to it, first mentioned by McGovern, and later expanded upon by David Sumpter. It makes perfect sense logically that closely rated teams should draw more frequently. The trick is whether this is profitable or not, i.e. is the market inefficient here? since Draws by themselves are meaningless. If the percentage of drawn matches shoots up to 50%, and the price in general plunges to odds-on, not a lot of good! 

Joseph's response was that:
It depends how you developed the system. If it was via back-testing a load of data there is always the risk that this is exactly what it is. How did the earlier seasons for the other European leagues perform? Have you got those figures?
There was no back-testing at all. I tried to explain how I stumbled across the draws being (relatively) good value in last week's post. Back testing wasn't even possible because the results were based on constantly changing Elo ratings and goal expectancies.

After the 2013-14 season, I realised that the time necessary to perform the updates each week and determine the selections wasn't worth it. A simple system based on the prices, and the differences between the teams, worked well enough. It works even better if the stakes are additionally weighted by Big 6 as well. 

Incidentally, yesterday's three selections by this basic (exclude odds-ons) method threw up two more winners in the games at Everton and West Ham United, with a loser at Stoke City. 

Joseph also made a comment on Derek McGovern’s book “On Sports Betting …And How To Make It Pay“ which I had mentioned had planted the seed of the idea that the draw might potentially offer value.
Joseph tweeted
It was actually a rather disappointing book which has not aged well as betting has evolved, and as I replied to Joseph, I very much doubt that he is paying Premium Charges to Betfair. We could ask him! He does have an account there, posting on the Forum under the name charwell as recently as Friday. I suspect a lot of self-published authors are better at selling books than they are making actual money. It used to be said that Those Who Can, Do; Those Who Can't, Teach. In the world of betting and trading, it's more along the lines of Those Who Can, Do; Those Who Can't, Sell Books About It.

** 21 January: The table was updated to reflect correct percentages on the All Draws column. Thanks to Joseph Buchdahl for pointing that out.

Thursday 18 January 2018

Beloved Draws and Wives

Prompted by Richard's above reply, I did look at the 0:0 and indeed the number of goals scored in matches sorted by the difference in the teams, using their implied win probabilities. I even threw in the Under 2.5 totals for you all.

The expectation would be that in games between evenly matched teams, there would be fewer goals and a higher frequency of the beloved, or hated, 0:0.

With 2130 games since the Pinnacle Closing Era, one quick way of seeing if this idea has merit is to sort the games by difference into deciles of 213 matches each.

The average number of goals per game is 2.72. By decile, with the first decile between the most closely ranked teams, the numbers are:
The results are as expected, with 45% of the 0:0 scores in the 'closest' 30% of matches. As I cautioned yesterday, without the 0:0 prices, whether this is a profitable strategy or not remains uncertain.

Fifteen 'Big 6' matches (of 168) ended 0:0, ten of those in either October, November or December. 

Marty left a comment on yesterday's post, perhaps thinking I am an LDS member, offering some marital advice:
If you get made redundant please don't forget to spend some of that spare time with your older wife.
Very droll Marty. When you get to my age, there aren't too many women older than me around, and talking of age, and multiple wives, I did like this tweet from legendary financier T Boone Pickens, who was recently in the news for calling it a day for his "energy-focused hedge fund he has run for the last two decades as his health declines". 

I guess at his age, energy starts to run out, but perhaps not his sense of humour. Asked his opinion on cryptocurrency, he replied:
For the record, he's currently on his fifth marriage. He can afford those divorces. 

Wednesday 17 January 2018

More Draw, Tense Situation

My post on the English Premier League Draw last week proved to be one of the most popular articles ever with esteemed writers David Sumpter (@Soccermatics) and Joseph Buchdahl (@12xpert) both commenting.

David wrote:

I hope David wasn’t disappointed by my research. In the days of 111% over-rounds, and minimum bets of trebles, the idea that the draw might offer value was of academic rather than practical interest. David publicised the idea when it was actionable.

Joseph wanted me to resuscitate the XX Draw system but the idea of going back almost four seasons, and re-activating an old spreadsheet, and processing 1,370 matches with each taking maybe 10 minutes, (i.e. 28 days at 8 hours a day), is a non-starter. This excludes the time for adding in newly promoted teams at the end of each season, so we’re probably talking about a full month in total. My wife would not be happy.

There’s also nothing to be gained from going back. The mention of the XX Draws was to demonstrate my long history with the Draw rather than to make a claim on my model at the time, which would be pointless given that it was put to sleep years ago.

If the XX Draws continued to be profitable, it’s highly unlikely that any extra profit would justify the time required to find them. If they turned into losses, it only confirms my suspicion that the days when an individual armed with an Excel spreadsheet could compete with the well-resourced likes of Starlizard are over.

The truth is that while the XX Draws were profitable, a simple strategy of avoiding matches with odds-on favourites was also profitable. 
Time isn’t free, and the reason I abandoned the model. Perfect is the enemy of the good. If I can find in five minutes a method of generating an ROI% of 10%, it’s probably not worth nearly two hours as a hobby punter to increase that to 11%.

Other comments on the article included:
I'd suggest me, and anyone on the Unders. 

Some readers will know that I call this the Perfect Draw, while others refer to it as a Bore or Snore Draw. I'll take a look at the 0:0 as time permits. 

Presumably the premise is that a 0:0 is more likely in games between two closely matched teams, and while overall the 0:0 makes up 32.7% of Draws in the EPL, when the difference in win probability is up to 30%, this percentage increases to 34.4%. Without the 0:0 price though, whether this is a profitable strategy or not remains uncertain. 

I took a look at the English Championship to see if some of the findings from the Premier League held up, and found that the simple no-odds-on filter again made for a profitable outcome, although much reduced by comparison:
I'll publish more Draw related data from other leagues in the future, likely in the summer. I have another trip with work starting next week which will keep me away from home until February.

A different angle on the draw being value when two teams are ranked as close comes from A Lucky A Day who tweeted:
This is not an area I've looked at, but the same logic would seem to apply. It would be interesting to have some stats on this. 

Speaking of stats, with the Australian Open this week, it's probably a good time to publish the results for the Men and Women since 2013 at this event. First the Men, where the favourite holds sway:
Nothing so clear cut on the Women's side of the competition:
Finally, for an, albeit self-published, writer, retired blogger James Butler demonstrates an alarming inability to understand some of the more subtle nuances of the English language. 

Hot on the tail of his confusing Technical Analysis with Fundamental Analysis, he now misunderstands his verbs, tweeting:
Indeed, nothing is for sale. Note the present tense being used there. Is. Words mean things, and apparently James missed that small, but important, detail.

I guess it is arguable that including links to sites where James’ books are sold is technically a breach of the “nothing is for sale” mantra, but I think 99.9% of readers understand what is meant by that line. It certainly doesn’t mean, nor is it intended to imply, that nothing will ever be for sale at some point in the future, but a book remains a long way off.

While the reference to writing a Green All Over book was mentioned as one possibility to fill my spare time should I be made redundant and while my younger wife is still working, the chances of any publication are certainly slim, if not none. The suggestion of a film based on the book was also a casual comment, not one that I intended to be taken seriously.

In the extremely unlikely event that a Green All Over book and film are produced, James can rest assured that the blog by-line will be changed to reflect this, and readers will be encouraged to both buy the book and see the film. I've heard it’s common practice after writing a book, to try and sell copies of it.

The theory that retirement leads to mental deterioration seems to have gained some traction in the light of James’ recent and frequent confusions.

I think I’d better keep working for as long as I can, lest I suffer the same fate! 

Tuesday 16 January 2018

NFL - Fly Bird Teams Fly

The NFL Division Round this past weekend wasn't the most successful for followers of the road teams.

In the first game of the weekend, the Atlanta Falcons, giving 2.5 points to the Philadelphia Eagles, were only the third road team to be favourite in this round, and lost the game, with the Overs also a loser. It shouldn't have been a surprise really, given that...
Tuck that little gem away for next season.  

13.5 point underdogs in Game Two, the Tennessee Titans lost by 21 points to the New England Patriots, but at least the Overs came in, even if only by one point.

The third game was a double winner with the Overs winning as well as the Jacksonville Jaguars who not only covered the spread (7 points) but won straight up at the Pittsburgh Steelers.

Finally, the New Orleans Saints were beaten on the final play of the game by the Minnesota Vikings. The 'official' spread was 5 points, and the game ended 24-29, so when the Vikings took a knee rather than attempt the extra point, (with no time left, the game was already won), anyone getting 5 or 5.5 (as many books had the line) got very lucky. Quite possibly the only time in NFL history that there were two punters on the field for a play. Overs was again the winner. 

For the Championship round next Sunday, the Patriots are currently 9 point favourites at home to the Jaguars, while the Eagles are again home underdogs (their starting QB was injured late in the season), this time getting 3.5 points versus the Vikings who are attempting to become the first team to play a Superbowl in their home stadium.

History favours the home team in this round overall, but road teams have the edge when favourites. The Overs are the totals play, but beware the small sample size.

For those who like trivia, two NFL teams have previously played a Superbowl in their home city. In 1980, the Los Angeles Rams played at the Rose Bowl, and in 1985, the San Francisco 49ers played at Stanford Stadium.

Saturday 13 January 2018

Probability, Difference And The EPL Draw

The Draw result in football has been a mild obsession of mine for several years. 

I’m not sure when I first stumbled upon the idea that the odds on the Draw might not be efficient, but it may well have been when reading Derek McGovern’s book “On Sports Betting …And How To Make It Pay“ maybe ten years ago. 

The book was published in 1999 but my interest in betting wasn’t re-awakened until discovering the Exchange concept in 2004, by which time some of the book’s content had become obsolete.

Much of the chapter on football betting dates back to a time when punters were far less sophisticated than today and bookmaker restrictions meant that for most matches, home teams needed to be backed in accumulators of at least five, and the draw and away selections in minimums of three. The typical over-round was 111%, a far cry from today 102% with Pinnacle and in theory close to 100% if you shop around and have access to several books.

McGovern intriguingly wrote:

Regular soccer punters will know that in football betting the odds are very much in the bookmaker’s favour. In a match in which theoretically all three potential outcomes – home win, away win, and draw = are equally likely, the true odds should be 2-1, 2-1, 2-1 [for younger readers, 2-1 is 3.0 in decimal odds]. But such odds give bookmakers no profit margin, so instead they will offer, say, 6-4 [2.5] the home team, 6-4 the away team, and 11-5 [3.2] the draw, the draw being longest price because bookies know that few punters ever back it. This produces a book of 111% giving bookies a theoretical profit of 11 per cent whatever the result.
Unless the expectancy of any goals is extremely low, or there’s a fix in place, the Draw will never be favourite, but the interesting part was that a book might be offering value on an outcome simply because the bet might not be popular.

Later in the chapter, McGovern talks about bookmaker Ron Wadey, who at the time owned five betting shops in the north of England. On the subject of odds-compilers, which such independent bookies used in those days, Wadey is quoted as saying:

“Their job is to come up with odds for a football match that will attract three-way support – for the home team, the away, and the draw, although I accept that the draw will never be popular with punters”.
Further on, McGovern writes:
Bookmakers freely admit that few punters back the draw in football matches. Punters want an allegiance in a game, to shout on a given team. Backing the draw is almost an admission that they can’t make up their minds.
The football punter in those days was clearly recreational.

After writing that roughly 30% of matches in the top two English Divisions in 1998-99 resulted in a Draw (implied odds 9-4 [3.25]) he observes that:
“Yet very often 12-5 [3.4], 5-2 [3.5] or even 11-4 [3.75] is available about the draw in a top-flight game. Bookies can get away with offering over the odds for the draw because they know it will attract little money, and it allows them to tighten even further odds for the home and away sides”.
This led to the logical conclusion that:
"a loophole could be exploited in matches in which bookmakers could not split the two sides, for instance offering 6-4 [2.5] the home win, 6-4 [2.5] the away win and 11-5 [3.2] the draw.
Bookies were saying, I argued, that there was absolutely nothing between the two sides, that an away win was just as likely as a home win. But by doing that they were also implicitly admitting that the draw was an equally likely result. Indeed you could argue that if the two sides are so evenly matched, a deadlock is the likeliest of all three outcomes. Therefore, the true odds of each outcome must be 2-1 [3.0], translated into 7-4 [2.75]  once the bookmaker’s in-built margin is taken into account.
If you could consistently get 11-5 [3.2] or more about a 2-1 chance, my reasoning went, profits were inevitable”.
What a lovely thought – inevitable profits. Nothing is usually this simple but it was an idea that stuck in my mind.

Around 2009, and in hindsight I was something of a pioneer in the field given the recent surge in interest, I started calculating expected goals (now referred to as xG) and deriving probabilities, and thus odds, for all goal related markets – e.g. match odds, over / under, Both Teams to Score.

My Excel spreadsheet maintained Elo based ratings for teams in the top five European Leagues (English Premier League, La Liga, Serie A, Bundesliga and Ligue 1). After each round of matches I would enter match data, and update the ratings. I would then enter the upcoming fixtures and the spreadsheet would calculate probabilities on various outcomes.

It was while entering data from completed matches that I discovered that for drawn matches, more often than should have been the case, the outcome was that the ratings for both teams would remain unchanged, or almost unchanged.

It wasn’t too difficult to reverse engineer these findings so that by entering an upcoming fixture, it would generate a figure for how much a draw would change the ratings. A number between -0.1 and 0.5 was a strong indicator that a Draw might result, with higher positive numbers indicating a home win, negative numbers an away win.

From this came the hugely successful XX Draws which were profitable for the three seasons (2011-14) I shared them, until a work promotion reduced my free time and I suspect my very basic xG calculations were about to be improved upon by far better resourced enterprises anyway.

The XX Draws included selections from the top five European Leagues, and the results from these years are below:

My model was also rather good at finding the Draw in matches where it was priced at 4.0 or higher, although the effort of finding an average of seven selections a season can't really be justified. 
I mention the 4.0+ (IP 25%-) mark because blindly backing the Draw at this price in the EPL is a losing proposition.
In a recent post, I published the results of backing the Draw selectively from the 2,120 matches played in the EPL since the start of the 2012-13 season. Those numbers used the maximum price for an apples to apples comparison with Soccernomics' numbers, but the Pinnacle Closing price is more realistic, and using these, the following table might be of interest to some of you.

The Big 6 and draws have received some recent attention for good reason - blindly backing the Draw in these fixtures has an ROI of 14.3%, a number that is easily exceeded by being selective on these games. 

To help make the table easier to understand, P is Probability, D is Draw, H is Home, A is Away, W is Win. The 'Difference' is a measure of how far from the favourite the other team is - the lower this number, the closer the two teams are. For examples, the Draw in matches between teams with a difference of 2.5% or less has an ROI of 40.3%, but a low sample size. 
For Premium Charge mitigation, you can do worse than blindly back the draw when it is priced at under 4.0, but a couple of simple additional parameters, such as excluding any matches where one team is odds-on, can improve returns hugely. 

I'll update these numbers in the summer, and may take a look at some of the other leagues in the meantime. 

Looking at today's games, and we have an odd situation with the Albion derby match, West Bromwich v Brighton and Hove. At the time of writing, Pinnacle have:
This 46.5% v 23.2% 'profile' hasn't been seen before. When the probability of the home team winning is .465, the average Draw and Away prices are 3.44 and 3.79 respectively. 

When the Away side is around 23.2%, the Home team has always been odds-on, 1.93 on average, with the Draw at 3.72!  

The Draw has only Closed at 3.1 or less on 29 previous occasions, (since 2012), and was a winner in 14 of them, so don't let that short price necessarily put you off. 

Has word of the EPL draw value finally got out? 

Wednesday 10 January 2018

Leading Bookmakers?

David Sumpter's interesting fresh look at Draw value in the Premier League included the below chart:

Note the explanation that: "Odds based on best odds from four leading bookmakers (Pinnacle, Bet365, Ladbrokes & William Hill)".

When it comes to Ladbrokes and William Hill, the term 'leading' can most certainly not be applied in the sense that these firms offer 'leading' prices. This is very mis-leading. 

As many readers will know, the Draw has long been of interest to me, and I keep track of these things.

Going back to the start of the 2012-13 season, there have been a total of 2,210 English Premier League matches. 

William Hill offered the clear best price 10 times, while Ladbrokes were hardly much better with a count of 18.

Bet365 were the best price in 327 matches, but far and away the best book, and one won't restrict you, is our friend Pinnacle. 

Pinnacle's early Draw price was the outright best 670 times, with their closing price on top 934 times. Pinnacle's early and closing prices were joint best in another 36 matches, and overall Pinnacle were best or joint best priced in 81.5% of matches.

As for backing the draw in Draw-4 matches (no team is odds-on to win, and the draw is under 4.0) the profit is 83.42 points from 944 matches, an ROI of 8.8%.

In all 167 matches between the Big 6, the profit is 28.73 points, an ROI of 17.2%.

Adding my Draw-4 filter improves this to 29.46 points from 119 matches, an ROI of 21.0%

Backing the Draw in every game would have lost you just 24.02 points, an ROI of -1.1%.

The results of the 2,210 games were Home Wins 45%, Away Wins 30%, Draw 25%. 

Remind me in May to update at the end of the current season.

Tuesday 9 January 2018

Work, Book And Doddy

I mentioned previously that towards the end of last year, my company offered me a year's pay to go away. They didn't phrase it quite like that, but unless anything dramatic happens in the next four days, it'll be an offer I will be passing on.

There are a few reasons, but the advice of an older family member who did retire when he was a similar age to me now, was that if I don't hate my job, to keep working as long as possible.

I think that's pretty solid advice. My job is not hard. It's not dangerous. It's not wearing me out physically. Mentally? Well in theory, it can get stressful when things go wrong and operations I oversee have issues, but in practice, I'm of an age now where I can keep things in perspective. It's not that I don't care; it's more that as you get older and become financially independent, you are free to do your best free of worrying about your job, an attitude which actually benefits both you and your employer.

Another big factor was what the heck would I do with myself if I wasn't working? I'm too young to take up golf, and I jokingly told my sister that "I'd start getting up later, and drinking earlier" but there was a grain of truth in that comment. It would be all too easy to get into a very unhealthy lifestyle once the theoretical structure of work is removed. 

I say theoretical because there's not that much structure right now. Another advantage of a long career is that life gets a lot easier. It's not really work. The nature of my job these days means that I visit the office maybe one day a week, and later this month am away for another nine day trip, which keeps things interesting.  

My suggestion to retire and go travelling was vetoed by Signora Cassini, since she is still working. As much as she says she's ready to stop, as a supportive husband, I think it's important that she stays productive and continues to work towards her career goals. She claims that she's already exceeded them, but luckily for her, I've managed to find more.

One option for my free time would be to write a book. In response to a Tweet from @statsbet recommending his followers read this blog from the beginning, the following exchange took place:
Ken Dodd! For those of you who don't know, that was not a compliment. It was mildly amusing though. When you support Aston Villa, a sense of humour is essential. 

However, the possibility of a Green All Over book certainly generated some positive interest. Here are just a few of the comments I received:
I think that a book would be a great idea. I've enjoyed writreading this blog for many years and a book based on your best posts would be great - Bob
A book is an excellent idea Robsy! Looking forward to seeing you at Mum's 90th - J
Unkle Booby - Mum tells me your finking of riting a book. If you kneed a proof some one to find speeling missteaks in it let me no.
So for now at least, I remain gainfully employed, reluctant to be the one to pull the trigger on what is a fairly decent income. Not to mix metaphors, but if / when the axe does fall, I'll be fine with it, and if that day is later than August I'll also be ahead of the offer financially.

One final comment is that more than one person told me that a person's attitude to spending changes once they're on a fixed income. It's a lot easier to justify that £1,000 expense if there's a pay day around the corner. I tried to find an article supporting this theory, but lost interest after stumbling across this comment:
I'm calling the police.   

Soccermatics Drawmatics

An article by author David Sumpter published at discusses his Premier League draw strategy which has come to the fore lately. I'll have a post regarding my own history with the Draw in the top leagues when time permits, but for now here is David's post in full, including "truly" shocking spelling mistakes:

If you had followed the betting advice in Soccermatics you would now be very rich

While writing Soccermatics I did something I had never done before: I bet on football. I did it as an experiment. I wanted to work out what paid off and what didn’t, but I also put “my money where my mouth is” and used some of my book advance to back the games my model predicted as winners. I wanted to truely test my skills as a mathematician.

I’ve written about the details of my betting strategy elsewhere: extensively in the book itself, then afterwards for the Economist 1843 magazine and more recently for Pinnacle Sports. In short, I used a statistical model to show that the odds for the Premier League have a weak longshot bias (which means it pays off to back the favourite) and a slightly stronger bias against draws between evenly matched teams, in particular matches between the big six. It was by exploiting these biases in the odds that my strategy made money.

I made a small profit during my experiment, about a 25% return over half a season. I was pretty pleased with myself and it made a good story for the book, but I haven’t gambled (much) since. I felt there were other things I could apply my skills to. As I wrote in the book:
All very worthwhile thoughts, but should I have taken my own advice? NO!!! This turns out to be a complete pile of sanctimonious bullshit…

I just made the plot below of the profits I would have made if I had invested £100 in my strategy at the time I made the model (at the start of the 2015–16 season) and bet according to the rules I described in the book.

My £100 would now be over £1800! In fact, in Soccermatics my bankroll was £500, so I would just now be sitting on ten grand if I’d just trusted my model! What a fucking idiot I am.

OK. Calm down, David. There are a few caveats here. The first thing to note is that from around the start of last season until the start of this season (matches 400 to 800) I would have seen my profits stagnate and slowly dwindle. It is only since September this year that the real profits have been made. In fact, when I last reanalysed this data for the Pinnacle article in October, I was far less bullish about the model.

Secondly, the big profits since September 2017 came during a period in which the big six in the Premier League have won alot of their matches. This helped my model, as did some high profile draws. The alternative universe, where I followed my own betting tips, would have seen me place £734 on a draw between Arsenal and Chelsea on Wednesday the 3rd of January (the last match shown in the figure). As Bellerin’s strike hit the back of the net for Arsenal to equlaise for 2–2 I would have been dancing around the room, singing the praises of the bookmaker which had given me pre-match odds of 3.51, providing me a profit of £1,842. This result, along with the Gunners 3–3 against Liverpool before Christmas, is extraordinary, and can definitely be attributed to luck. The current surge of my betting strategy is unsustainable.

So let me emphasise (and not just to make myself feel better) that the really big, recent rise in value of the Soccermatics strategy is due to a bit of very helpful randomness created by Arsenal and other big six teams.

There is, however, reason to believe that the Soccermatics strategy works in the long term, albeit with a lower rate of return than it is currently experiencing. The bookmakers edge in the data I used to assess the model is 1.1% on average, so the model significantly outperforms random bets throughout the whole period, not just the last few months. I reassessed my strategy after reading an article by Church of Betting showing a long-term profitablity of backing draws between equally strong teams. This analysis includes more historical data than I used in the book and also looks at other leagues (which Church of Betting shows don’t tend to have the same bias).

It is always possible to find statistical patterns in historical data that appear to give profits, only to find that they don’t hold in the future. We are fooled by randomness. Joseph Buchdahl’s excellent book — Squares & Sharps, Suckers & Sharks — carefully analyses a whole range of different betting strategies and finds that they usually fail to beat the market in the long term. He argues that a true winning strategy must have (1) a proven record on future performance and (2) have some sort of ‘explanation’ of why it works. His own strategy, based on using Pinnacle odds to beat other bookmakers, passes both these tests.

My model can make some claim to pass these two tests, albeit on a smaller data set. I first tweeted about my model at match 50 (in the graph above), I submitted my model to the publishers around match 100 and the book was published around match 300. So the profits shown are based on predictions of the future, not an historical fit to the data. I also have some form of ‘explanation’ for my model: in the Premier League punters bet against the big six, probably becuase they support other big-6 teams. When two big-six teams meet then all the focus is on one of the two teams winning and the draw is forgotten by the punters and the bookies. These circumstances are somewhat unique to the Premier League, because there are so many ‘just for fun’ gamblers involved in the market and six teams with a worldwide following.

It is easy to be wise after the fact and to talk about the big bets I could have made. I did put £30 at 3.51 on a draw in the London derby (and on the Arsenal vs. Liverpool game, where I got odds of 3.61, before Christmas) and I was pretty pleased when the equalisers went in at the end of both matches. But the truth is that I’m not the sort of person with the nerve to put £734 on a single match (even if the bookies would let me). And I don’t think I ever will be. Profits change much more quickly than people do.

I’m sorry about this, but I can’t help being sanctimonious again. If you do want to be a statistical gambler then you need a set of skills. I would encourage everyone to get those skills, because they are both useful in your everyday life and greatly increase your possibilities on the job market. My betting model is one of many examples in Soccermatics of how maths gives us an edge in the game and in the rest of life. I would never encourage anyone to take up gambling full time, but I would encourage everyone to learn more maths and statistics. It is the safest bet of all.

Acknowledgement: Thanks for Joseph Buchdahl ( for double-checking my calculations. Using a slightly different way of calculating ‘fair odds’, but reimplenting my model, Joseph found a similar growth curve to the one I show, but climbing to £1400 instead of £1800.

Monday 8 January 2018

Alabama Crimson Tide v Georgia Bulldogs

The decision to play the Unders in the Jacksonville Jaguars v Buffalo Bills Wild Card game turned out to be correct, with just 13 points scored in total. The decision to skip the bet on them to cover wasn't so good.

In the final game of this round, the Carolina Panthers covered the spread versus the New Orleans Saints to complete a nice weekend.    

The College Football season comes to an end tonight with the Championship game between 3.5 point favourites Alabama and Southeaster Conference rivals Georgia. This is only the fourth season of College play-offs, and with only 11 games in the books, there are not too many trends. 

One thing that does stand out is that the lines tend to be way off in these games. Eight have been 'wrong' by double figures, with half of those by 28 points or more. 

Favourites are 6-5 straight up, 5-6 against the spread. In games where the line is less than 7 points, the underdog is 5-2 ATS, with the two losses both this season as the favourites both covered the three points they were giving.

Although these play-off games are all technically neutral, the game is being played in Atlanta, which for those of you who flunked geography, is in the state of Georgia. While Georgia play their home games in Athens, they have already played, and won, two games in Atlanta this season, including the SEC Championship game last month.

As for the total points, the line is set historically low at 45 points. The only two games with similarly low totals (44.5 and 46.5) both went Under, but again, the sample is very small so don't go crazy. 

I'll be on Alabama -3.5 and Under 45 points.

Sunday 7 January 2018

Wild Card Edges

Halfway through the NFL Wild Card weekend, and if you took my advice last week and backed the road (away) teams, you are in good shape. 

The Tennessee Titans were getting 8 points but didn't need any of them as they beat the Kansas City Chiefs 22:21, the first time under the current play-off format (since 2002) that a Wild Card team getting more than 7 points won straight up.

In the second Saturday game, the Atlanta Falcons getting 5.5 points beat the Los Angeles Rams 26:13.

Today's road teams are the Buffalo Bills (+8.5) at the Jacksonville Jaguars and Carolina Panthers (+6.5) at the New Orleans Saints. 

Big road 'dogs have a poor record in this round, so beware the Bills, but if you have to bet on this game, the Unders is where the value lies. In the 19 games where the home favourite was giving 6 points or more, the Unders has come in 13 times with one Push.

Not much proper football action this weekend. Along with most of the country, I have little interest in the FA Cup this weekend until the Mother of all Derbies on Monday night, correctly selected by BT Sport as the tie of the round.

I'm actually old enough to have seen the birth of this rivalry, with my first experience back in August 1974 before things had escalated to where they are today, with the M23 derby now ranked up there with some of the best rivalries in the world. 

El Clasico, Superclasico, Old Firm, M23...

Finally the NBA Beast System continues to be profitable. Backing the Overs when the total is over 215.5 in now 94-71-5 
The over 218.5 subset with  more manageable number of sections is doing even better with the below record: 

Friday 5 January 2018

Big Six Draw Value

We can blame Joseph Buchdahl @12Xpert, but as I mentioned back in November in regard to League Two Aways:

The downside of the publicity is that the esteemed Joseph Buchdahl Esq. became involved, along with his small army of 5,000 followers, so the edge on these will now be gone. Fun and lucrative while it lasted though.
It does now seem almost certain that the League Two Aways System will show a significant loss for the first time since 2011-12.
After 309 matches this 2017-18 season, the system is down by 25.6%, with big losses in November and December.

I should probably blame @statsbet more than Joseph, as it is he who brought this now tarnished nugget to the latter's attention, or more crucially his 5,000 followers.

The latest, golden for now, nugget that statty is "drawing" the world's attention to, is the value in backing the Draw in the English Premier League. 

I wrote on this in my final post of 2017, and since then the profit on my simple system (backing the Draw in matches where neither team is odds-on) has since climbed to 20.83 points, an ROI of 23.1%.

It should be noted that blindly backing the Draw in this league this season is profitable, although with a reduced ROI of 8.5%. 

When asked by statty if Wednesday's Arsenal v Chelsea draw was value, @Soccermatics author David Sumpter wrote:
What 'these big matches' means is unclear, but the Draw is priced at 3.2 or higher in most (89%) EPL games.

Backing the Draw in these games would have you in profit by 5.34 points (ROI 2.7%).

If 'these big matches' refers to games between the Big 6 (Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham Hotspur) then the ROI this season is 5.8%. (Only four non Big 6 teams have crashed the Top 6 domination since 2012).

Here are the numbers since the dawning of the Pinnacle Age, both for all Big 6 matches and for those where the Draw price was 3.2 (Implied Probability 0.3125) or greater:
David Sumpter's tweeted his thoughts on the Premier League Draw, writing:
I would say that any strategy that makes a profit over a whole season is worth following. 5 years for sure. The problem often is however that the return is very small and variance large. Making it not much ‘fun’.
Hopefully, further exposure about the Draw here on what has been described as "the world's number one sports trading blog" won't see the value being lost overnight, but with some big players involved in the Premier League these days, it won't last for ever.

While most individuals might not find betting on the Draw 'fun', their money should be swamped by that of the big players and sharp punters like readers of this blog. That this is not yet happening is a little strange. 

Just for fun, I looked at the "no-odds-on" Draw bet in lower leagues in England this season. 

Championship: Currently down 24.06 points from 199 selections
League One: Currently down 37.98 points from 214 selections
League Two: Currently down 58.00 points from 231 selections 

Only in the National League, curiously still referred to as the Conference at Football Data, is this profitable, with an ROI of 20.56%, +43.96 points.

For the record, I'm teasing @statsbet. He frequently DMs me to ask my opinion, and we were both on the Arsenal v Chelsea Draw this week, and both had a financial interest in Crystal Palace not losing to Southampton. Statty was on the Palace win, while I had a more cautious lay of the home team. After trading at 1.5 to be relegated, Crystal Palace are now looking more likely to qualify for Europe.