He described his theory in 1956 in the journal " Bell Journal teknikal systems ." Essentially , the system is progressive by Kelly rates in accordance with the rates that more players at a higher probability of winning and less at a lower probability of winning .  

For years, many professional players , people involved in sports betting , and math time to try out the system in various ways. Most of them agree with each other that it is better to risk less than the recommended criteria cell, and in the best case, this system should be used as a guide , not a rule . Often you can hear the players say they use 1/ 2 or 1/4 Kelly . This — just simplified version of the formula of the Kelly criterion .
One of the reasons to use the Kelly criterion as a guide , is that following it without any adjustment excludes from the calculation of rate equation and the player they acquired experience. Since it is actually a mathematical equation , some argue that the system eliminates Kelly human reasoning , while others notice that no system is perfect and that the real rates it needs to be amended on the basis of experience.
The main problems associated with Kelly criterion include :  

This control rates tend nepostoyansto that can prevent any attempt to apply sound money management . The shorter the odds , the more your bet . But with this system you can risk 20-50% of your bankroll on one bet . Would be a serious blow if the short and long odds will you lose . Take an example — if your bankroll is 1000 euros and you bet at odds 2-1 , Kelly says that if the probability of your winning is 60 % , you have to make a bet of 399 euros! This is a large amount — 40 % of your budget. Most professional players agree that players should use only a fraction (about 50% ) of the amounts recommended by the Kelly system .  

    With regard to risk , this method requires the rates of many players out of their zone of psychological comfort . It seems that when you follow the Kelly criterion is not even some room to breathe ! This can be psychologically burdensome. If we talk about rates , when using this system players will need to take into account what they really willing to risk , as well as their comfort zone .  

    Calculations regarding your next bet , based on your input data and data rassityvaemyh using Kelly formula . There are online calculators that can help you provide the correct size of your bets. However, if any of your data are incorrect , the system will not work. Accuracy is necessary .  

    Although over time the system can bring considerable income , there is no upper or lower limits. This means that the application of the Kelly criterion can lead to a large number of individual bids at risk most of your bankroll. One big loss can wipe out huge wins .  

Usually, most players can not successfully use the Kelly criterion , because they can not accurately assess your winning percentage . Almost all players overestimate their real advantages and usually this is the reason that make sports betting players lose using the Kelly criterion .
For years players have successfully used the Kelly criterion , but if used carelessly or blindly follow it , the results can be disastrous. So remember — "Be careful player and use the system wisely Kelly ."