Looking Back at the 2022 ZiPS Projections

Before we get to the 2023 ZiPS projections, there’s still some unfinished work from 2022 to do. Looking at which projections went the most wayward is definitely an exercise that makes me soul cringe a bit, but in any model, being wrong is an important component of eventually being right. Calibration is a long-term project, and while chasing greater accuracy in mean projections isn’t likely to result in any huge bounty — there’s a reason projection systems are so tightly clustered — there’s still improvement to be had in things like calibrating uncertainty and long-term data.
Let’s start with how teams performed versus their projections:
Team | ZiPS | Real | Difference |
---|---|---|---|
Baltimore Orioles | 64 | 83 | 19 |
Los Angeles Dodgers | 93 | 111 | 18 |
Houston Astros | 90 | 106 | 16 |
Cleveland Guardians | 78 | 92 | 14 |
New York Mets | 88 | 101 | 13 |
New York Yankees | 88 | 99 | 11 |
Atlanta Braves | 90 | 101 | 11 |
Seattle Mariners | 85 | 90 | 5 |
St. Louis Cardinals | 88 | 93 | 5 |
Philadelphia Phillies | 83 | 87 | 4 |
Toronto Blue Jays | 88 | 92 | 4 |
Arizona Diamondbacks | 71 | 74 | 3 |
San Diego Padres | 89 | 89 | 0 |
Milwaukee Brewers | 87 | 86 | -1 |
Tampa Bay Rays | 88 | 86 | -2 |
Colorado Rockies | 70 | 68 | -2 |
Chicago Cubs | 77 | 74 | -3 |
San Francisco Giants | 85 | 81 | -4 |
Kansas City Royals | 70 | 65 | -5 |
Pittsburgh Pirates | 68 | 62 | -6 |
Chicago White Sox | 88 | 81 | -7 |
Detroit Tigers | 73 | 66 | -7 |
Minnesota Twins | 86 | 78 | -8 |
Los Angeles Angels | 81 | 73 | -8 |
Oakland Athletics | 68 | 60 | -8 |
Texas Rangers | 77 | 68 | -9 |
Boston Red Sox | 88 | 78 | -10 |
Cincinnati Reds | 74 | 62 | -12 |
Miami Marlins | 82 | 69 | -13 |
Washington Nationals | 76 | 55 | -21 |
Teams have gotten a bit more polarized in how they’re run in-season. Looking at the in-season ZiPS projections, roster strength has varied much more in recent years than when I started doing this. It wouldn’t be surprising to see the mean absolute error — for an exercise like this, I want to use the simplest tool that gets the point across — creep up over time. That is the case here, as the MAE of 8.3 wins is above the ZiPS historical average of 7.5 (not including 2020). ZiPS underperformed its usual matchup vs. Vegas, only going 17-13 in over/unders as of the date of release (April 6); historically, ZiPS has averaged 19-11. Read the rest of this entry »