If we talk about money management and discipline, then I think it has related to all of the gambling games. But how about sports betting? But I don't know but I think in sports betting, we play with probability too.
With sport betting probability is correlated with expected win in that way that casino always wins. Its like roulette. If you have 50% chance to win than you will almost double when it will happened. Almost 
.In poker probability and expected win/loss is not set by casino. You, players, are setting that during betting and that's the moment when skill comes in. When it's going too far and probability is too low than you quit. Just like in trading. When price break support than expected loss is increasing rapidly while probability of profit is descrising - you need to quit and "left your money on the table".
Ability of quitting. That's my point. Ability to not panic hold. No matter if its coin or its hand with dual pairs and bidding is going too far.
Your way of comparison on trading with gambling may be good for you but for all the people doing will not be able to follow it in such a way. Percentage of winning and seeing indicators to speculate the price will not be the same anytime.
We may consider it panic hodl or being safer side. Pure luck and ideal move on trading is not at all a same. That is my point.