Comparing a baseball player's physique to that of your average NBA player, you might think they're just not athletes of the same caliber.
But in a strategy-heavy sport where you only succeed every third time at bat you need more than fitness. Good baseball players are also very self-confident, have exceptional mental fortitude and are great at mind games.
"Baseball is impossible without psychology: impossible to play, and impossible to appreciate fully as a fan,... Watch any game, and most of what you see is thinking."