Mark Slavin

“solid player is a mental game fish if they: Change a proven winning strategy because they are running bad/hot. Never recognize when someone has played well against them and/or believe everyone they play against is bad and just gets lucky. Try to win every hand. Think the outcome of a hand can be changed by shouting, praying, or playing a favorite hand. Get frustrated when a bad player plays badly and they even educate them as to why they are bad. Feel like a failure when they lose a hand that was played profitably. Think the solution to running bad is to stop playing or change stakes. Read a poker book cover to cover and think they know everything in it. Watch some of Phil Galfond’s training videos and think they should now be able to crush the game like him. Believe that they are cursed or that other people are luckier than they are. Believe it’s possible to own another player’s soul. Play more hands when they are winning/losing. Play fewer hands when they are winning/losing. Play badly when the stakes are too small for them to care. Allow things to get personal with another regular. Tell bad beat stories to anyone that will listen, while doing nothing to improve how they react to bad beats. Say “one time.”
― Jared Tendler, The Mental Game of Poker: Proven Strategies For Improving Tilt Control, Confidence, Motivation, Coping with Variance, and More