Basically: A chalker is a fat girl that you can not fully wrap your arms around when you give them a hug.
The guy who's so bad the coach will scratch him just to count the score, shots, hits etc. on a chalkboard. In the worst case, a chalker will be chosen even when the team has 5 or less usable players.
Guy 2: No shit they never play you, you're the chalker.
Guy 1: yea well i heard the chalker on the other team got cut! I'm there.