I understand all the problems that a sports player betting against themselves can cause, but what is the harm caused by betting for oneself or one's team to win (note I am not saying win by X points, just win).
In players contracts, they could have clauses for getting X money with each win, how would this be different than a player putting X money on a game, and winning if they win?
Note: The reason I am just saying winning is because if something such as winning by X points was done, the player would be trying for that goal, compared to the goal of winning (which would be the same goal even if he was not betting)