A wad of gum stuck on a player's hat brings good luck. It is bad luck if a dog walks across the diamond before the first pitch. Some players believe it is good luck to step on one of the bases before running off the field at the end of an inning. It is bad luck to touch the baselines while running off and onto the field between innings. Lending a bat to a fellow player is a serious jinx.
Some players actually sleep with their bat to break out of a hitting slump or stay in a groove.
If a pitcher is throwing a perfect game or a no-hitter, never speak of it while it's going on. The last person to shoot a basket during the warm-up will have a good game. Wipe the soles of your sneakers for good luck. Bounce the ball before taking a foul shot for good luck. To continue a winning streak, wear the same clothes.