People who are bowling crappy and yell, 'ONE BAGGER!', when they get a strike. Yes, you're bowling bad, I don't care.
People who claim to have given up, but then bowl a good game. They self handicap themselves, so that if they bowl bad, they have an excuse. If they bowl good, they somehow overcame adversity.
When I grab a different ball and someone sarcastically says, 'oh, that must be the problem'.
This one guy always used to ask me how heavy that ball was. He insisted on throwing 16 (I throw 15), but he almost fell over at the line every time.