When I remarked that I would vastly prefer to have the division series round of MLB's postseason go seven games, because the current best-of-five feels "engineered to produce sweeps and injects an enormous crapshoot effect into an already overly-random system," a reader wrote in to point that statistically speaking, the crapshoot effect in a seven game series is only marginally lower than in a five game playoff:
Baseball is inherently a random game, so there's no real way to structure the playoffs to avoid the possibility of an inferior team winning. A battle between an 81-win team and a 100-win team would be a fairly lopsided playoff matchup. Using the log5 method (which is the generally accepted sabermetric method) and running 50,000 simulations, the 100-win team won a 5 game series 71.5% of the time and a 7 game series 74.6% of the time. So, the 7 game series is less random, but it's not a huge difference.
Interestingly, the just-concluded Cubs-Dodgers series was almost as lopsided as the simulation above - the 97-win Cubs against the 84-win Dodgers - and after watching Chicago go down to defeat , I'm of two minds about my "seven games are better" thesis. On the one hand, I think that even though the effect of the extra game(s) on the randomness of the outcome is marginal in the extreme, there's still a sense in which a seven-game series feels like a more just reward for a great regular season than a five-game series, and losing 4-1 or even 4-0 leaves the losing team's fan base with a better taste in their mouth than the "blink and you missed it" feeling that a three-game sweep inspires. (When the Red Sox lost 4-0 to the vastly-superior A's in the 1988 and 1990 ALCS, I felt like justice had been done; when they lost 3-0 to a similarly-loaded Indians team in 1995, I felt like I'd been cheated out of a real postseason appearance.) On the other hand, it felt like they could have played best-of-seventeen and the Dodgers still would have swept the Cubs: Alfonso Soriano would have ended up 3-for-42; Ryan Dempster would have walked 21 batters in three starts; Manny Ramirez would have hit ten home runs for the Dodgers, and the outcome would have been exactly the same. If you can't do more than the Cubs did in three high-stakes games against a markedly inferior team, maybe you don't deserve a fourth chance at it.