This act of sportsmanship and encouragement is given following either a good play, a play that was ruined, or for just plain pep.
The slap ass is limited too, but does not exclude, coaches of other sports, as well as other sports players.
NOTE: This is the ONLY instance in which another male may slap another male's ass, and not be considered gay by fellow teammates. On-lookers, fans, and friends are not subject to this requirement, and thus may consider you gay.
Friend 2: Yeah, he even got a slap ass afterwards.
Onlooker 1: Did you just see that guy give a slap ass to the other guy? I think they may be gay.
Onlooker 2: No, they aren't. They play baseball.
Onlooker 1: Ohhhhh.