The Postseason
Twelve teams, four rounds, and a format designed so the best team frequently does not win.
What it actually is. Twelve clubs qualify, six from each league: three division winners and three wild cards. The top two division winners in each league get a bye. The others play a best of three Wild Card Series, then a best of five Division Series, then a best of seven Championship Series, then the World Series.
What somebody who knows the game gets out of it. Short series are close to coin flips and this is the most important thing to understand about October. A club that is ten percent better than its opponent wins a best of five only about 55 to 60 percent of the time, because baseball's game to game variance is enormous relative to the gap between good teams. That is why the phrase best team in baseball stops meaning anything after September, and why the correct read on a first round exit is almost never that the team was overrated.
The numbers worth knowing. Twelve of thirty clubs qualify. A 100 win team beating an 88 win team in a five game series is roughly a 60 to 40 proposition. The bye is worth a meaningful amount, mostly by skipping a round of variance.
What people get wrong about it. The bye is not purely an advantage. Five days without competitive baseball is a real disruption, and the teams that receive it have historically not performed as well as their records suggest, though the sample is small enough that this is a live argument rather than a settled fact.
At Little League and travel ball. Youth tournaments use pool play into single elimination brackets, which is even more variance than a five game series. This is worth saying to a family directly: losing a bracket game on a Sunday is not evidence about the team, it is one game.
Batter's Eye: look up anything in baseball