Verlander’s Decline in Historical Perspective

Justin Verlander was excellent yesterday against Toronto, throwing seven shutout innings en route to the Tigers’ 11-1 demolition of the Blue Jays. He was not quite as dominant as the Verlander of 2011 and 2012, but that is a pretty high standard. Actually, the 2013 Verlander has not really measured up to that standard all year. Verlander won both the Cy Young Award winner and Most Valuable Player in the American League in 2011, then was just as good in 2012. He pitched a cumulative total of 489 and a third innings and had a 2.52 ERA during those seasons.

By reasonable standards, Verlander’s 3.54 ERA and 112 innings pitched at the halfway point of the 2013 season is very good. By his own recent standards (as well as that being set by his 2013 rotation mates Max Scherzer and Anibal Sanchez), it is somewhat disappointing. It is not that Verlander’s 2013 is bad in itself, and it is hardly the Tigers’ main main problem — that would be the bullpen (solution: move Verlander to the ‘pen!). Still, Verlander’s apparent decline might concern some people. My intention is not so much to evaluate Verlander’s current true talent or possible health problems, but to put his recent performance in historical perspective relative to pitchers with similar stretches of success.

One can see the obvious sources of Verlander’s ERA issues relative to the past couple of seasons right away, of course. His 2013 strikeout percentage is just under 25 percent, which, although very slightly lower, is right in line with 2011 and 2012. He is walking more batters, though, at 8.6 percent, as opposed to around six percent the previous two seasons. What is probably having the biggest impact on his runs allowed, though, is BABIP. Verlander’s BABIP for 2011 and 2012 combined was .255. So far in 2013, it is .333. I would guess his true talent BABIP is somewhere in between those figures (a brave stance, I know), but that is not my main concern here, as I said above. His FIP is right in line with previous season (3.02 this year, 2.97 in 2011 and 2012 combined); his xFIP is a bit worse (3.47 this year, 3.21 the previous two).

It is also worth noting that Verlander’s fastball velocity is down, which is sometimes an indicator of looming injury issues. However, as Jeff Zimmerman wrote earlier this week in his injury-watch roundup. Verlander is 30, and that is well into the decline phase for typical pitchers in most respects: velocity, strikeout rate, and general performance. In that respect, none of this should be a surprise.

Age-related decline is one likely factor, and there is always our old friend regression to the mean, too. Yeah, Verlander just signed a really big contract, even if this is all he “really is” at this point, it is not all that worrisome, something Jeff Sullivan touched on this spring. ZiPS and Steamer see Verlander as ending the season being worth around five or six wins (depending on whether you prefer at RA- or FIP-based value metric), which, if not as amazing as his last two years, is still quite good.

Yet there may be a feeling that this is still disappointing for a pitcher of Verlander’s caliber. After all, from his 2009 season in which he really “broke out” as one of the best pitchers in the league through last year, he has averaged a little over seven wins a year. Are pitchers of this quality perhaps a bit different?

Let’s leave aging curves and regression aside in favor of some general historical perspective. From 2009 to 2012, Verlander produced about 28 Wins Above Replacement. To get a list of similar performances, I did a query to find all such similar streaks for pitchers starting in 1955, that is, all instances of four consecutive seasons in which a pitcher put up at least 28 wins total and went on to pitch a fifth season. The query generated 49 instances of this. Given the nature of the query, some pitchers appear more than once. For example, Tom Seaver had four such streaks (four consecutive seasons with a cumulative WAR of at least 28). Pedro Martinez, Randy Johnson, and Bob Gibson each show up five times. Greg Maddux had six such streaks, and Roger Clemens had nine. Verlander shows up once with his 2009-2012 streak.

The average cumulative WAR for a pitcher in this group over the first four years considered is just under 32, for an average of about 7.9 wins a season. In 37 of the 49 instances, the pitcher has a lower WAR in the fifth season than his average of the previous four. In the fifth season, the average is about 6.2 wins. Verlander has 28 wins in his 2009-2012 streak for an average of about seven wins a season, and seems to be in line for five to six wins, which sounds about right in line with the rest of the results.

Slightly lowering the minimum for win-value over the first four years to 25 generated similar results. There were 96 instances of a four consecutive WAR total of at least 25 since 1955, and in 65 of those cases the pitcher had a lower WAR in the fifth season. In this group, the pitcher averaged about 7.3 WAR over the first four seasons, and about six in the fifth, much like Verlander is projected to end up.

Again, nothing about the fifth-year declines is surprising. Sure, some pitchers defied the odds and were as good or better in the fifth year. But for the most part, regression to the mean and expected aging for pitchers took effect. Given the parameters we set up, the pool was made up of excellent pitchers, so it is not surprising that they were still excellent as a group in the fifth year, too, if not quite as good.

This obviously does not put Verlander into the same category as Martinez, Johnson, Gibson and the rest as far as pitching greatness. One might take it to be negative: hey, Verlander is on the decline! But again, not only is that not surprising, but to me, it seems to be more reassuring. If this is just age-related decline and regression, then that lessons concerns about lurking injury issues. Moreover, an age-related declines are not always rapid. If Verlander is “only” a six win pitcher at this point and loses a bit each year, the Tigers still probably have at least four years of Verlander being a very good-to-excellent pitcher. Sure, the last few seasons of the contract might be ugly, but that is pretty much true of every long-term contract.

Justin Verlander is probably not what he once was. But with a bit of historical perspective, this is not surprising, nor is it likely to be devastating.