Stepladder
The "stepladder", named so as the bracket resembles a step ladder is a variation of the single-elimination tournament; instead of, in a 16-team tournament, the #1 seed facing the #16 seed in the first round, the bracket is constructed as to give the higher seeded teams byes, where the #1 seed has bye up to the third round, playing the winner of game between the #8 seed the #9 vs. #16 winner. This setup is seldom used best-of-x series as this may yield long waiting times for the teams afforded the bye, while the teams that played in the earlier rounds would be spent when they reach the latter rounds.
The Big East Men's Basketball Tournament used this format in a 16-team, 5-round format. The PBA Tour uses the 4-player, 3-round format (sometimes a 5-player, 4 round format). The University Athletic Association of the Philippines Basketball Championship uses this format (4-teams, 3-rounds) only if there's an undefeated team, otherwise it uses a single-elimination format.
While the Nippon Professional Baseball's Climax Series has been called a "stepladder" playoff with only three participating teams (2 rounds), it functions mostly as a single-elimination tournament with 3 teams, and is structurally the same with a 6-team, 3-round playoff.
Read more about this topic: Playoff Format