In the last few years, MLB used a post-season bracket, rather than reseeding after each round. The brackets are set up so that the third best division winner places the third wild card, while the top two wild card teams play for the right to meet the team with the best record in the league. Basically, the highest division winner in each of the first two rounds gets to face a wild card team. In the NL this season, where all the wild card teams are likely to be second place teams, all worse records than any division winner, this works great.
The AL this season offers the reason against the bracket. The best three teams in the league all likely come out of the AL East. That means the top two wild cards, the Yankees and the Red Sox, play each other in the first round. Then the Rays, face the winner of that round, making the first two rounds of the AL post season a playoff for the AL East title. If the wild card team emerged from the other pair in the first round, the Rays will not play them.
In fact, if all three division winners make it to the second round, the Rays would play the Yankees or Red Sox anyway, since a Wild Card always is a lower seed.
Brackets give MLB two advantages:
- Easier planning for possible which allows them to be a bit more efficient in reserving hotel space and flights.
- More fan engagement with bracket games.
So it seems to me that brackets are here to stay.