They are basically strung together sit-n-goes. You will be at a table with 6 players or 10 players. Whoever wins(1st place) gets moved to a table with all of the other table winners. Double shootouts usually have 100 players so there are two rounds. Triple shootouts are usually 6 player tables and have 3 rounds (216 entrants). They are pretty fun to play, lot of dead time between rounds though since everyone has to finish before the next round starts.