View Single Post
Old 04-26-2007, 05:38 AM   #9 (permalink)
Ganchrow
Moderator
 
Ganchrow's Avatar
 
Join Date: 08-28-05
Location: Forest Hills, NY
Posts: 4,453
Default

Quote:
Originally Posted by 3put View Post
Take Pointbet as an example.
They closed after not paying in months and many players tried to lose their balance by arbing.

I guess big Pointbet-underdogs were used often in this process.
But quite counter-intuitive, at least to me initially, using your formulas, it seems that betting on big favorites is much better in this situation.
The article above only addresses a single bet at a time. Once you start considering multiple bets simultaneously, whether the underlying events' outcomes are mutually exclusive (as would be the case when considering a perfect hedge), independent (as would be the case with bets on different games), or non-mutually exclusive dependent* (for example a side and a money line on the same game), the equations in the above article no longer strictly hold. This will be addressed in the next article in the series.

Quote:
Originally Posted by 3put View Post
There are situations where the goal is to Minimize Expected Growth with respect to certain restrictions on betsize.
In mathematics these are known boundary conditions and they can often complicate problems immensely. Fortunately, in the case of single-bet Kelly the solution is simple. Just bet the smaller of the Kelly stake and the maximum bet.

Quote:
Originally Posted by 3put View Post
Take Pointbet as an example.
They closed after not paying in months and many players tried to lose their balance by arbing.
You don't need Kelly to tell you that this is a bad idea. If a book won't pay you if you win, then a bet at the book isn't a hedge but rather a waste of time and bandwidth.

Of course, if a player thinks the book in question has a non-zero probability of repayment and he can find a profitable arb involving that book, then he certainly could use his funds at the distressed book as a semi-hedge of sorts, provided he discounted any holdings at that book by a reasonable estimate of repayment probability.


* Dependent includes both correlated and uncorrelated bets. After all, it is possible for two non-mutually exclusive bets to be uncorrelated, but not independent. Consider for example, a bet on Team X winning a game versus Team Y and a bet that Team X and Team Y's finals scores will be within 1 of each other. If Team A's win and lose probability are equal, as are the win-by-1 and lose-by-1 probabilities, then while the two bets are uncorrelated, they're obviously not independent.
__________________
Ganchrow is offline   Reply With Quote