So What’s Up With That St. Louis Cardinals PECOTA Projection?
Last week, Baseball Prospectus released their famous PECOTA projections. Every year, BP drops the forecasts their algorithms have generated for baseball nuts to pore over, obsess over, and ultimately nitpick. For the most part, projection systems are conservative, and with their forecasts regressed towards the mean, they typically don’t spit out too many results that look far out of line.
Nevertheless, sometimes there are projections that appear puzzling. One example is PECOTA’s projection of 71 wins for the Orioles, a forecast that was analyzed in-depth by former Editor-in-Chief of BP Sam Miller at ESPN. However, perhaps the most shocking projection from PECOTA this year is the forecast for the St. Louis Cardinals: 76 wins.
One of the more important things to remember when trying to understand a seemingly mystifying projection is that in reality, you and the projection system probably have more in common than you think. After the New England Patriots stormed back from a 28-3 deficit in this year’s Super Bowl, fans everywhere laughed at the statistical models that estimated the Patriots’ odds of winning at close to 1%.
Yet, of course the models forecast the Patriots as extreme underdogs when they were down 25! Teams that are down that much almost always lose, and the models were right to discount the Patriots’ chances. Often, when a projection system makes an unpopular projection, the forecast it is making is more intuitive than it may initially seem. Is something like that going on with the Cardinals? Or do we as humans have insight into why PECOTA could be underestimating St. Louis? Let’s take a look.
First, a discrepancy could appear between our and PECOTA’s expectations for the Cardinals because PECOTA doesn’t care about the Cardinals’ recent win/loss totals or track record. Where we see a solid franchise with a history of success, PECOTA merely sees a collection of statistical inputs. If something about those underlying statistical inputs indicates that the Cardinals recently haven’t been as good as they appeared, that could explain part of the 76-win projection.
But that isn’t the case. The Cardinals had a fine record of 86-76 last year, but their Pythagorean record was 88-74. Moreover, BP’s third order winning percentage, which estimates a team’s “true” quality by adjusting for sequencing luck and strength of schedule, pegged the Cardinals as an 89-win team. So there’s no evidence PECOTA is down on the Cards because of good luck last year; if anything, St. Louis suffered from bad luck.
If the Cardinals suffered a number of subtle but significant losses to their roster over the winter, that also could explain why PECOTA is so down relative to our expectations. Again, that doesn’t appear to be the case. They did lose sluggers Matt Holliday and Brandon Moss, but neither made much of an impact in 2016, as they combined for a total of 1.1 rWAR. If anything, the Cardinals upgraded their outfield in signing Dexter Fowler to a five year, $82.5 million deal. They did deal Jaime Garcia, a talented lefty starter, but that was from a deep starting staff (well, one that was deep, prior to losing uber-prospect Alex Reyes to Tommy John surgery, an injury which occured after PECOTA was published). On the whole, the Cardinals’ core just hasn’t lost much talent this offseason.
So to explain the discrepancy between the public perception of the Cardinals and PECOTA’s perception, we must simply look at the projections themselves. Scrutinizing the actual granular predictions of a projection system should really always be prerequisite #1 for critiquing said projection system, and in looking closely at the individual forecasts for the Cardinals, it becomes obvious why PECOTA’s projection for the team in its entirety is so poor: PECOTA simply believes that most of the Cardinal players aren’t very good.
The Cardinals’ two best position players in 2016, Matt Carpenter and Yadier Molina, combined for 8.4 WARP last season. PECOTA projects them for just 2.3 WARP each in 2017. Fowler, coming off a wonderful season with the Cubs, projects for just 1.6 WARP. Outfielder Randal Grichuk, who broke out for 2.4 WARP in 2016, is projected for half that total in 2017. Shortstop Aledmys Diaz, who shockingly posted a .299/.369/.510 line and 4.1 WARP last year, projects for 1.7 WARP. In fact, the only Cardinal starter projected to improve from last year is Jhonny Peralta, who projects to improve from -0.3 WARP to a measly 0.1 WARP.
The Cardinals’ starting staff, which conventional wisdom has dubbed a strength, is likewise viewed quite poorly by PECOTA. With Reyes now on the shelf, the best ERA projection belongs to staff-ace Carlos Martinez at 4.20. The highest WARP projection belongs to Mike Leake at 1.8 WARP. Essentially, PECOTA doesn’t forecast any of the Cardinals’ starters to be above average.
So this doesn’t seem like a case where a seemingly odd projection, upon closer examination, actually appears fairly in line with conventional wisdom. No, this seems like a case where most baseball fans consider the Cardinals to be a team full of good baseball players, while PECOTA sees the Cardinals as a team made up of mediocre ball-players.
Does this mean that PECOTA is *wrong*? No, as PECOTA’s forecasts are based on reams of historical data that hint at how the future of each ball-player could play, and if PECOTA looks at the Cardinals as a below average team, it undoubtedly has its reasons. However, at the same time, we, the baseball viewing public, have every right to disagree. For instance, it is not hard to envision Carpenter, a 31-year old three-time All-Star, not dropping off as significantly as PECOTA foresees. Molina, a former star, may very well age far more gracefully than PECOTA expects. Martinez, a 25-year-old who posted a 135 ERA+ last year, surely is expected to beat his 1.7 WARP projection. The list of Cardinals projected for middling seasons in spite of relatively strong recent play goes on, enough for us humans to reasonably see the Cardinals as an above-.500 team.
Most of us are understandably skeptical of PECOTA’s projection for the Cardinals, and after looking at the forecasts more closely, it seems like fans and PECOTA will just have to agree to disagree. Still, it would be folly for us to disregard this projection entirely. PECOTA may prove out to be correct, if players like Carpenter and Molina age quicker than expected, and if the Cardinals’ staff proves more shallow than we think. In the end, there’s only a few more weeks until we’ll have our chance to see.