What do you think is the biggest leak in a player's cash game that, if corrected, could increase their win rate?
I'll start:
Leak: Not understanding the dynamics of multiway pots (which happen a lot in cash games). For example, understand that your premium pocket pair does much better heads-up than it does multiway.
Fix: Your game will improve as you improve your reading of the board and getting better at letting go of a hand that was great preflop but is losing its value as the hand progresses. Don't just focus on your pair of Aces. Look at the board texture. You may still have that same top pair after the turn, but if the board has straight and or flush possibilities (that don't help your hand), and there are multiple players in pot, and they are eager to keep putting their money in, you probably don't have the best hand.
The major leak in a cash player is the psychological side and lack of mindset. Some players tend to play cash games as if they were playing tournaments, and cash is a boring game, sometimes we stay 200, 300 hands withouth anything important happening, not even getting dealt pocket aces. We must get used to it. Tournaments are full of emotion, there's the payout, the bubble, the short stack, the jumping, the big hit, the final table, you name it!
Cash is not a game of action, it's more like chess where we must have solid foundation on postflop game, player profile and mindset. We must be balanced and think it through on every corner. We should never respect our opponents more than they deserve to be respected but also we cannot disrespect anyone on the tables, because even recreational players will hit good hands.
The major leak is to go to the tables with our egos, thinking that we are either better or worse than our opponents, and this is not the objective: the main factor is to play in position against recreational players and have tons of patience because nothing exceptional will happen for a long time. And this is the way the game is.