Definition: In table tennis, many tournaments conduct rating events, where only players who have a rating under a certain cutoff amount (such as Under 2000 in the USA) can enter the event.
Sandbagging occurs when a player (the sandbagger) attempts to lower his rating score below his true playing level by losing matches on purpose before an upcoming tournament, so that he can play in a rating event that is lower than his true rating. Assuming none of his opponents are sandbaggers, he will have an unfair advantage over his opposition, and will be likely to win the event.
For those who are interested, I have written some further thoughts on the reasons on why sandbaggers sandbag, and what can be done to stop sandbagging.
