Sandbagging

Sandbagging means deliberately playing below one's real strength so that a rating, the number used to estimate competitive playing level, becomes artificially low. It can involve intentionally losing or drawing without real effort, resigning unusually early, or creating a deliberate sequence of losses.

The intended advantage usually comes later: qualifying for a lower-rated section, receiving pairings against weaker players, or competing from a rating that does not represent the player's real strength. The online regulations of the International Chess Federation (FIDE) and major chess platforms treat intentional rating manipulation as a fair-play violation, meaning a breach of the competition's rules for permitted and honest play.

Not every losing streak is sandbagging. A player can lose repeatedly because of fatigue, experimentation, or a normal drop in form. The essential feature is the intent to make the rating artificially lower. It is related to boosting, which pushes a rating in the opposite direction, and can overlap with smurfing when an account is deliberately kept far below the user's true playing strength.