Adam Wainwright did not have the season many envisioned he would in 2016. A closer look reveals a far less effective curveball than in years past.

Adam Wainwright is famous for his curveball. When they hear his name, Cardinals fans think of knee-buckling 12-6 drops. Wainwright’s twitter handle is @UncleCharlie50, a nod to the pitch that made him an ace for many seasons. The signature breaking ball caused fear in opposing hitters, especially when they got behind in the count. They knew they couldn’t hit Wainwright’s bender because, well, nobody could.

From 2012-14 (the period between Wainwright’s season-long injuries), batters whiffed on over 37 percent of their hacks against the Cardinals’ right-handed hurler. When the count got to two strikes, Waino went to his curveball 44 percent of the time, more than twice as often as any other pitch. The results were incredible: Wainwright averaged nearly 120 Ks per season with his curveball, while holding batters to a .231 slugging percentage against the pitch across all counts.

FanGraphs assigns a value to each pitch based on the decrease in run expectancy when a pitcher uses a certain pitch. Waino finished in the top two in curveball value in each season from 2012-14. For the cumulative results in those three years, Wainwright’s curve was the best in baseball. In fact, his curveball was worth 40 percent more than the number two curve, which belonged to A.J. Burnett.

Wainwright is by no means a one-pitch pitcher. Nevertheless, if an opponent could pick one pitch to neutralize for a game, it would choose the curveball. Much of Wainwright’s struggles last year had to do with poor defense and poor luck. However, the numbers also show a more concerning trend: Wainwright’s curveball was hittable in 2016.

Trouble With the Curve

Few things went as planned for the Cardinals in 2016, but Wainwright’s curveball may have been the biggest surprise. By most measurements, the curveball was still Wainwright’s best pitch. He got more strikeouts with that pitch than any other, he generated the most whiffs with that pitch than any other, and held opponents to their lowest average and slugging percentage against that pitch relative to the others. However, Wainwright did not dominate with his curve like he did in seasons past. Opponents slugged .363 against his curve, up from .223 prior to last season.

Perhaps we should have expected some decline given Wainwright’s age, but 140 points is too much. Besides, Wainwright was too good from 2012-14 with his deuce to expect that large a drop off. The increase in isolated slugging is even more concerning. That number more than doubled, going from .060 in the years before 2016 to .127 last season. Isolated slugging is effectively the ratio of extra bases per at-bat. In other words, power output against Wainwright’s curve jumped by a large margin last season.

Wainwright gave up home runs on his curveball twice as often last year as he did in his entire career before then. The fielding wasn’t good last year, but fielders don’t cause more home runs. Given how often Wainwright throws curves, it is also unlikely that the homers were a fluke. The fact that Wainwright generated whiffs on less than 30 percent of his curveballs also indicates more fault on his part.

So all of this is nice to know, but how can the Cardinals fix the problem?

Usage Patterns

One glaring difference between Wainwright’s career curveball usage and his curveball usage in 2016 is when he decided to throw the pitch. Wainwright reinvented himself a bit in 2012 after the injury, so I will stick to his usage patterns since that season. In total, Waino threw his curve from 2012-14 about as often as he did in 2016. However, he used to be three times more likely to throw it when he was ahead in the count than when he was behind. While he still uses the curveball more when ahead, the contrast is no longer as stark. Here are a pair of tables from Brooks Baseball demonstrating the difference:

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Adam Wainwright Pitch Usage 2012-14
Adam Wainwright Pitch Usage 2016

It is hard to tell whether or not this is a good or bad change. All we know is that batters do better when ahead in the count. Thus, some of Wainwright’s problems with the curveball can be attributed to when he uses it. If he is more likely to throw it in a 2-0 count, then batters are more likely to connect with it. Of course, every pitch shows this trend, so it isn’t clear whether or not he benefits overall by throwing the curveball less often when behind in the count.

The other issue is that batters are less likely to swing if they are ahead in the count. For his career, Wainwright has kept up a relatively constant whiffs/swing ratio with his curveball regardless of the count. However, total whiffs goes down if the batter doesn’t swing as often. In fact, Waino generated whiffs on 36.4 percent of swings against his curveball when behind in the count in 2016. When he was ahead, that number was actually lower, at 32.5 percent.

The point is that batters were much more selective when ahead in the count. If Wainwright threw a curveball, they could afford to wait until either it was down the middle or they got an easier pitch to hit. Thus, the batting average and slugging percentage against should go up, even if the contact rate is the same. More selective hitters get to swing at better pitches, and thus end up hitting the ball harder. Sometimes, baseball is that simple.

Of course, that isn’t the full story, either. Wainwright’s curveball usage accounts for part of the problem, but not all of it. Waino also threw the ball up more often when he got behind. Sometimes pitchers do this thinking the batter is taking all the way. In some of those cases, the pitcher ends up getting burned. Wainwright gave up all five of his homers against the curve when either even or behind in the count. Here is an indication of why:

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Both of the above heat maps are from Baseball Savant. The left one shows Wainwright’s curve when even or behind in the count. The one on the right is his curveball when ahead in the count. On both graphs, most of the red is concentrated in the lower half of or below the strike zone. However, there is still a lot of red and orange in the top half of the zone on the left. Batters are hitting those pitches up in the zone, but they don’t have the chance when Wainwright gets ahead in the count.

Should Wainwright Stop Throwing Curveballs in Hitter’s Counts?

While the results seem to indicate that Waino is worse with his curve when behind in the count, that is not cause to stop throwing the pitch when in such situations. Every pitcher gets worse when behind in the count. Wainwright is worse off when behind in the count regardless of what offering he chooses. Even the pitches up in the zone are somewhat unavoidable. When behind in the count, missing low costs much more than it does when ahead. Therefore, pitchers can’t aim lower and use the space below the strike zone as a safety net when behind in the count. As a result, some pitches go higher than desired.

Ultimately, all this data shows is that one of the reasons that Wainwright’s curveball was hit more often is that he used it in different situations. It doesn’t necessarily indicate a lesser pitch. The drop in whiffs/swing is a little troublesome, especially in 0-2 counts. That perhaps is the biggest indicator of a decline in the quality of the pitch. At the same time, Waino did not experience the same large drop in other counts. There were small drops, but nothing else alarming. The truth is that while Wainwright’s curveball was less effective in 2016, the pitch’s quality did not drop as much as the raw numbers indicate.

I agree with Mack Hoyt’s assessment that Wainwright will bounce back in 2017. However, after digging into the curveball numbers, I think there is a lower ceiling than usual. Yes, I just told you that the traditional stats overexaggerate the problems, but I also recognize the reasons for concern in there. We cannot ignore the whiffs/swing ratio. Wainwright’s curveball should be better than those statistics indicated, but his Uncle Charlie will never be as dominant as it was during that 2012-14 stretch.

Photo credit: Jeff Curry – USA TODAY Sports

  • Zach Gifford

    Thanks for the link here, guys. Probably had to do a bit of digging to find that one.

    On the curveball heatmaps, I think both represent a big problem with his ability to drive the pitch down in the zone in 2016. Even when ahead in the count, his most distinguished core was piped right down the middle. Not exactly a recipe for success. Compare that to when he was ahead in 2014:

    Here, he either nailed the very bottom of the zone, or was forcing batters to swing over the top of his pitch low and outside the zone.

    I don’t have any idea, really, as to why he had trouble getting the pitch down. But it seems that is one of the major factors, and hopefully one he can correct.