Originally posted by Vaughany
If the argument is that you can't make a kelly stake because the probability of a 50/50 shot could easily be 20%, then you should be avoiding making any bets below +400.
The point I am making is that people often overestimate their edge. If a bookmaker opens a line giving you a 50% edge, and money doesn't immediately move it towards your position, then its MUCH more likely that your estimation is off.
You have to define a winning probability. You can account for margin of error, but beyond that anything less than some version of kelly staking is minimizing your EG. Anything else you might as well just be picking winners.