Originally posted on 12/03/2018:

Specific answer: if your estimates are exaggerating your edge, Kelly will hurt you. Go beyond full-Kelly and you're already into counterproductive territory, go beyond twice and you'll actually lose money longterm regardless of your edge. One approach is to adjust your edge back to something realistic.

General answer: as a new sports bettor, you probably shouldn't use Kelly. NBA is quite efficient, and if you're predicting 78% when the market thinks 50% ..... you've made an error somewhere :-) On that scale, it's highly likely to be leakage.


I'd suggest working on the models for quite a while, then when you start, stake small - say 1% of your bankroll. Get yourself some practical experience for at least a year.