A Calcutta, or "auction pool" is an event held in conjunction with a golf tournament, horse race, or similar contest with multiple entrants. Participants in the Calcutta bid among themselves to "buy" each of the contestants, each contestant being assigned to the highest bidder. The bids are pooled, and after the contest the pool is divided among those players who won the winning contestants at auction, divided according to proportions agreed upon in advance (often in the same proportions as the prize money awarded in the event itself).

This is similar to pari-mutuel betting, in that the winnings are awarded from the total pool of bets, but differs in that only one player can bet on any one contestant.