Reviewing the Preseason Standings Projections
The FanGraphs staff made its obligatory preseason picks before the season (naturally), and I think it’s safe to say that none of us have psychic powers. My picks of the Angels and Blue Jays to win their divisions — they’re not looking so hot right now. In my defense, I was just blindly going along with what our preseason WAR estimates told me. OK, not the greatest defense, but I figured Steamer + ZiPS + FG-created depth charts could produce better guesses than I could on my own. Especially with the roster changes that have happened lately, I thought it would be a good time to revisit our projections. The Angels came up the series victors against the Blue Jays in their recent four-game Battle of the Disappointments, but both teams are still far below the expectations put on them. However, let’s examine: could they actually be good teams who have just been unlucky?
Most teams have played somewhere around 110 games this season. That leaves plenty of room for unpredictability. If you flipped a coin 110 times, you’d expect to get about 55 heads, right? Well, the binomial distribution says there’s only about a 49.5% chance of the heads total being within even three of that (somewhere between 52 and 58 times). MLB teams are pretty different from coins — they’re a lot more expensive — but I think you can apply the same principle to them. The above calculation for the coin assumes the “true” rate of heads is 50%. What would we see if we were to presume our projections’ estimated preseason win totals are actually representative of the “true” win rates for each team? The following table will show you: Read the rest of this entry »