Is Kelly Optimal For All Betting Tips?

Money management strategies help the punter towager by the corresponding ratio. For example, if the
choose an optimal stake, and even though Kelly isaccuracy ratio of the betting tips for a home win is
known to be the best strategy of them all, it is not0.55, then when one bets on a home win, he should
necessarily true for all types of betting tips.multiply his wager by 0.55 to lower the risk.
This article summarizes possible ways to improveIf one's betting tips don't include a probability of a win,
Kelly's strategy for different types of betting tips.he should start with estimating this probability. One
First, let's emphasize Kelly's strengths andsimple way to do that is by calculating the ratio of
weaknesses:home wins, draws and away wins to the total number
According to Kelly's, the wager for each outcome isof games in the season. These proportions can be
calculated in the following way: w * (p-(1-p)/(odds-1)),used as probabilities of a win and no other correction
where w represents the wealth of the punter and p isfactor will be necessary. This method is less accurate
the probability of a win. For example, if your wealth =then the previous one, since it uses average statistics
1000$, p = 50% and odds = 2.5, then the wager yourto estimate the probability of a win.
have to place is equal to 1000$*(0.5 - 0.5/(2.5-1))=166$.The methods described above help punters to
If the probability of a win (p) is estimated correctly, thencalculate their optimal wager. However, these methods
the calculated wager will be optimal in a long run. If,won't help you choose the outcome to bet on. For
however, it is wrongly estimated, then using Kelly'sexample, when you distribute your wager between
won't do the trick.two of three possible outcomes, the long run profit will
What are the possible ways to improve Kelly'sbe maximal. The only way to calculate the optimal
strategy when the probability of a win is incorrect orwager for each outcome is by using data-driven
unknown?algorithms. In this case, the wager should be distributed
When one's betting tips include a probability of a win, itbetween matches whose outcomes can be estimated
is necessary to determine how accurate thisautomatically given historical data only. The output of
probability is for home/draw/away wins. It can be donethis algorithm is the value of the wager for each
by ratio of several successive tips to the total numberoutcome. The optimization criterion for those algorithms
of tips provided. This ratio can be used as a correctionis, of course, a maximal profit when betting odds are
factor for a wager estimated according to Kelly's. Toknown.
use this correction factor it is enough to multiply the