Thursday, 22 March 2012

A Thousand Words

Marky stopped by, as he always does on my anniversary, to post a comment on the subject of P&L blogs - why he never drops off a gift while he's here, I don't know. He wrote:

I agree that P&L blogs can be tedious but I think a readership often like to have an idea of what the author is aiming for from the blog.

I had a comment on mine today alluding to this and it reminded me of what people liked to read when I started. They wanted to follow my journey and it's hard for them to do that if there's no roadmap.
I probably should have made it a little clearer that I have nothing against blogs that INCLUDE some P&L, it's the blogs that are comprised solely of this that bore me to tears. For example:
Next month I am aiming for 20% profit. I`ve had a great start this month (September) 16% so far. Using only my own system.
For me, some kind of reasoning about how this 20% profit next month is going to be achieved would be interesting. One of the better blogs out there, the Football Trader's Path, touches on this subject with this post, but while SoccerDude's blog does include his P&L, it is by no means what I would call, or what I mean by, a P&L blog. Do the P&L postscripts add anything to the blog? Not in my opinion - in fact, I don't even look at the numbers, but the text preceding it is usually worth a read, and the numbers are quite innocuous.

The big problem with actual numbers is that they are meaningful only to the writer, not to the readers. we are not all equal. Some of us are hobbyists, some of us are full-timers, some of us are young, some of us are old, and £10 means more to some than to others, so if you post up a profit, or a loss, of £10, some readers swoon, others roll their eyes, and others don't even notice.
Is the above more interesting than "Detroit may have lost their game at Denver last night, but in decent form this month and getting 8.5, a price of 1.95 represented value against a team who recently lost at home to Cleveland (on a par with Detroit) and were blown out last time out at home to Dallas"?


BigAl said...

It would be more interesting if

a) You'd mentioned it before the match. Being completely honest, would you have used this as an example had the bet lost?

b) Instead or as well as saying "represented value" stating what you made the correct price - perhaps both what you believe a 50-50 handicap should have been, and what the price should have been at +8.5.

Have you thought more about your statement regarding edge and level stakes? Every time you mention it, you actually argue against something else.

To clarify, I am saying "if you can’t show a profit to level stakes you don’t have an edge” is incorrect.

Your initial replay was "A system that profits long-term to level stakes has an edge." (correct)followed by "A system that loses to level stakes, doesn't" (not always correct)

You also stated "If a system cannot show profits at level stakes over an extended period of time, then no alternate staking plan in the long term can produce a profit." Incorrect.

You then moved the goalposts: "It would be most interesting to read Big Al's revolutionary theory on how you can show a level stakes profit without an edge, or a level stakes loss with an edge". You possibly won't even understand why this is different.

Anyway, have a think about:

a) Someone with an edge misjudging the size of their edge.

b) This same person using a staking plan based on their perceived edge.

c) the fact the edge or perceived edge will vary depending on available prices.

Alternatively, don't think about it and simply stick to your public assertions that you are correct.

BigAl said...

Oh, sod it, rather than try and relate it to sports betting let's take the simple route.

Cross the floor from your roulette table and take a seat at the blackjack table.

How do you think the professionals win? They plug away all day taking hundreds of negative EV bets before pouncing when the deck is favourable with large bets.

"If a system cannot show profits at level stakes over an extended period of time, then no alternate staking plan in the long term can produce a profit."

If they play level stakes all the time, they lose in the long-term. Their alternate staking plan produces a profit.

Any arguments? Presumably you'll attempt to come up with some sort of different interpretation of your statement.

Average Guy said...

Intersting debate guys.

Brett Rodgers said...

Hopefully you are having better success than I am. I am trying to get back to breaking even this NBA Season. I wish that I could make some right bets. This season is just so off. My halftime betting is helping a little bit.

Tony said...

Big Al:
a) "someone with an edge misjudging the size of their edge" - if they have an edge, cassini has already said that to level stakes they sbould be in profit, so a system that is in profit to level stakes is correct from what i can see? Just because the person with the edge misjudges that they can make profit to level stakes by playing a system of some kind of "revolutionaty" staking system is not cassini's fault.

b) Why use a staking plan if your edge is profitable to level stakes?

c) The fact the edge or perceived edge will vary depending on the odds available.

Available prices determine the edge, so if the prices are not there, the edge is not there, so the bet is therefore not there.

To summarise i think you are pick

Tony said... arguments with cassini for the sake of arguing.

Omtomyour second statment regarding blackjack. Blackjack is a game of skill, not chance, so i personally dont see how an edge is sports betting is comparable? Predicting the outcome of a set deck of cards based on what cards you have previosly seen dealt is different to predicting the winner/loser of a particular sporting event based on the previous number of minutes/plays viewed in the game? Eg, the dealer rarely fumbles a King making the play void after 10 consecutive low cards compared to a quarterback throwing an interception for a returned touchdown after an 11 play 90 yard drive

Tony said...

Apologies for the bad spelling, fat fingers on my i fone. Start of my second comment reads "onto your". Plenty other mistakes too though

BigAl said...

Hi Tony. With respect your points are incorrect.

a) I mentioned the situation where someone misjudges their edge to demonstrate why Cassini's statement is incorrect. That said, almost every successful sports bettor will misjudge their edge. Basically this is because there is almost always someone who knows more, or is simply superior at estimating prices every time you have a bet (not the same person every time of course).

So, to make it simple, let's assume his edge is always 3% lower than he thinks.

His bets at what he perceives to be 1% value are actually -2%. His bets at 5% are actually +2% etc. etc.

Nonetheless, his staking plan will still involve having bigger bets when there is a bigger edge. So, depending on the distribution of bets at different edges, he can quite conceivably come out on top even if he has more negative value bets than positive value.

There's no proviso in my argument that this is the case every time. I'm merely demonstrating it is possible.

b) Pretty much covered above. Of course you should bet more when you have a bigger edge. A good staking plan is not only key to success (as already demonstrated) but it's also key to making the most of your edge. There are different considerations to make when deciding how much to bet (i.e. bankroll etc. if you take a kelly approach. You can use modified Kelly, or other simpler plans)

c) if the (perceived) edge isn't there you don't bet. But, as in a), that's not to say you don't end up having negative ev bets.

d) Of course blackjack is a game of skill. So is successful sports betting.

The comparison is that although a successful blackjack player will knowingly have negative ev bets, and the sports bettor will do so without meaning to, the principle remains the same.

I appreciate what you are saying about sports being a game of chance and, yes, there are some pretty random events, but we're talking long-term here so,from a very simple perspective, chance events will even out. Or, quite possibly, the most adept sports bettors will be able to successfully cater for these seemingly random events in the way they price matches.