3 ms·

To add to the complications of picking the size of bets, you will always find that you can get more money matched on a loser than you can on a winner... so even

To add to the complications of picking the size of bets, you will always find that you can get more money matched on a loser than you can on a winner... so even after identifying 'value' bets and using Kelly to size your stakes, you may find out that you never quite get enough money on the winners and that will limit your profits too! (Edit: getting the money matched only applies to bookies / betting exchanges, the equivalent problem for tote betting is that the price of winners will often be worse than your algorithms predicted)

PaulRobinson 9y ago
Exactly - getting matched is a big problem, and is the main way that bookmakers are able to prohibit winners. Most people in the UK have had their stakes limited after a couple of winners, and it's almost become a joke. Betfair and other exchanges provide more opportunity, but if your Kelly output is telling you to put £5k on a horse on a Tuesday evening AW track race, you are going to have to spend some time thinking about how you _actually_ do that without having the odds spiral in: markets respond to liquidity, and you are liquidity. There are some papers on how to deal with this, but none of them have a solid answer. My solution was to put in the amount Kelly advised and if I didn't get fully matched, c'est la vie!