St. Louis Cardinals: Sorry, Adam Wainwright Is Just Getting Old

The St. Louis Cardinals 2017 rotation is filled with question marks, and Adam Wainwright is a major concern.

Following a 2015 season lost to an Achilles injury, Adam Wainwright fell flat in 2016 for the St. Louis Cardinals. He had a career-worst ERA and FIP and his highest walk rate since 2007. His strand rate (LOB%) and groundball rate (GB%) were nearly 5% below his career averages, and his HR/FB rate soared.

Yet, somehow in the 2016 mess, there’s an optimistic feeling that Wainwright will bounce back and be “Wainwright” again. Carly Schaber and Dan Buffa discussed this possibility nearly a month ago, while last week Cardsblog took a similar stance.

However, there’s really no reason to believe Wainwright can rebound for the St. Louis Cardinals in 2017. Before I dive into player comps and statistics, let’s face the facts. Adam Wainwright will be 35 years old. He has by no means been healthy through his career, missing parts of 2008 and 2015 and all of 2011. That profile isn’t a recipe for a bounce back candidate.

Most fans are optimistic that Wainwright can put his 2015 Achilles injury fully behind him. It at least seems reasonable that a pitcher might not look like himself after missing a full season, but that he would rebound afterward.

I found twenty pitchers (including 2012-13 Wainwright) since 2006 who missed the majority or all of a season to injury, and compiled their stats for their first and second seasons back.

None of these measures changed significantly from the first to second season following injury. WAR/150 scales a pitchers Wins Above Replacement to 150 innings pitched, to provide a constant base to compare across seasons. On average, these pitchers actually got slightly worse in their second season returning from injury. The pitchers’ ERA, FIP, and xFIP remained effectively the same from year one to year two.

Limiting the sample to the five pitchers who missed time due to a lower body injury, the results are similar. However, these pitchers did improve on their average innings pitched by twelve in the second year and marginally improved their WAR/150 by 0.1. Again, their ERA, FIP, and xFIP did not significantly improve or worsen from season one to season two.

Based on this assessment, it would be overly optimistic to think Wainwright will be better next year than he was in 2016. These twenty pitchers were, on average, the same from the first year after injury to the second. Age was not likely a factor, either, as the average player age at the time of injury was just under 29 years old.

Adam Wainwright’s Age Is A Major Concern

Additionally, Wainwright’s age is against him and the St. Louis Cardinals. I generated average aging curves using FanGraphs data for starting pitchers and relevant statistics. To do this, I tracked every starting pitcher with >100 IP (1,463 seasons) in consecutive seasons beginning in 2006 (when PED testing began) and noted the change in relevant metrics during those consecutive seasons.

I then charted the average changes and average values for pitchers aged 22-39. Each chart uses a starter’s age-29 season as the base year, then adjusts for the average change at any given age. The value for any metric in the base year is its average among the sample pitchers.

So, for example, the average starting pitcher increases his WAR by 0.3 from his age-24 to age-25 season. Additionally, the average starter loses 0.7 WAR from his age-31 to age-32 season.

Back to the St. Louis Cardinals and Adam Wainwright. Those hoping for a Wainwright rebound might start by saying his LOB% drop was the result of bad luck. The ways starting pitchers age, however, suggests differently:

One obvious takeaway from this analysis shows that around age 34 to 35, starters tend to see a significant drop in LOB%. Wainwright turned 35 in August of 2016. Starters’ strand rates tend to move to an entirely different, lower tier after this point. The 75%+ strand rates we’re used to seeing from Adam Wainwright are probably a thing of the past.

Many fans believe that Wainwright’s 7.0% walk rate (BB%) last season will decline in 2017 when he’s healthier.

Next, fans argue that Wainwright’s HR/FB rate of 11.8% was unlucky. Yet, from 2008 to 2013, he averaged an 8.5% rate. His 5.3% in 2014 was as much of an outlier as his 11.8% rate last year.

Additionally, pitchers, on average, give up more home runs as they age. With Wainwright entering 2017 at 35 years old, it is unlikely that he will significantly improve his HR/FB rate. An average outlook might see Wainwright having an 11.0% HR/FB rate next year, only slightly better than his 11.8% in 2016.

One might argue that Wainwright’s .330 BABIP was also unlucky, and that we should expect it to regress to his career average of .295. While that is true to some extent, the data shows that, on average, pitchers fare slightly worse on balls in play as they age.

Admittedly, there is more room for error with BABIP. Yet, there is still a clear trend in favor of higher BABIPs. Here, the base value was set to .000 to show how much BABIP at a given age differs from the age-29 base year. Going forward, we might expect Wainwright to allow a BABIP 5 or 10 points higher than his career average to this point, which would mean a .300 or .305 rate.

Further, Wainwright saw his GB% fall to 43.8%, compared to a career rate of 48.3%. If he could get that rate back up to his career levels, he might see overall improvement next year.

However, it is unlikely that Wainwright will improve this metric next season. On average, pitchers see their GB% fall every season after turning 30 years old. While an uptick is possible, it likely won’t be nearly up to his career average level. It is worth noting, though, that Wainwright had an elite season in 2014 with a GB% of only 46.3%.

I’m not here to say that Adam Wainwright is a bad pitcher. Last year, as measured by FIP-, he was 2% better than average (98 vs. 100). His high ERA can be attributed, to some extent, to bad defense and bad luck. But he is getting old, and as pitchers get old, they get worse.

Next: Five Cardinals Feeling the Pressure

I still expect Adam Wainwright to be an average or slightly better MLB starting pitcher, which is even more valuable if he can stay healthy and handle 200 innings. But Adam Wainwright is no longer an ace, and it is unfair to expect him to return to that form. Time will not treat the St. Louis Cardinals ace differently.