Isolated stretches of four random baseball games are almost always meaningless, at least in the context of how we view a team’s or a player’s performance. Sometimes they grab our attention, like when Aristides Aquino homered in four straight. Other times, they don’t – the Miami Marlins won four straight games on three separate occasions this year, and both the Dodgers and Astros lost four straight twice. I’ll bet you’d be hard pressed to find someone who remembers those stretches. There are a lot of baseball games in a season, after all.
So, how do Aquino’s homers, the Marlins dominance, and the Dodgers futility tie in with today’s titular character, Adam Wainwright? Well, he recently had one of the best four game stretches of his career after going 4-0 with a 0.33 ERA in his first four September starts.
This article isn’t about Wainwright’s four-game brilliance, though, except for the role that it plays in his 2019 revival. His 3.98 ERA this season would be his best since the injury-shortened 2015 season and his 3.2 RA9 WAR, which is based on runs allowed instead of FIP, stands as his best since 2014 by more than two full wins. As of this writing, Wainwright is among the most-improved pitchers by Fangraphs’ version of WAR (+2.1). Part of that was due to injury – he spent 2018 battling elbow issues and on the Injured List – but the former ace hadn’t been effective even when healthy since 2015.
To steal a line from John LaRue stealing a line from Ben Clemens, when a player rebounds like this, “theories for what has changed abound.” He’s throwing his cutter more often and more effectively. He’s retooled his curveball and is leaning on it more frequently. He believes in himself again! Let’s add another to the basket: Adam Wainwright figured out how to complement his Uncle Charlie with his fastball.
Pitch tunneling is all about the flight path of the baseball and how similar the flight of one pitch appears to another before they break in separate directions. Curveballs are probably the toughest pitch to tunnel – most have a “bunny hop,” meaning they go up a little bit when they’re released from the pitcher’s hand before they break down. And while you can’t really get rid of the hop, you can disguise it with the threat of a high fastball.
The hop is a giveaway without the chance that it could be a high fastball. Now, that doesn’t mean every curveball you throw needs to be after a high fastball. You just need the batter to consider the possibility that a pitch which starts up could be a curveball or a fastball.
The next part of the disguise is location, and not just location at the plate. Where does the ball look like it’s going out of the pitcher's hand, and what does that first read tell the hitter? Wainwright’s curveball moves about twelve inches more to his glove side than his fourseamer. With that in mind, consider how he deployed the pitches in 2016 and 2017:
And think about where those pitches have to start in order to reach their final location at the plate:
From the hitter’s view, if you see the ball start outside immediately out of the hand, you're thinking fastball. If you see it start high-and-inside, think curveball. Milliseconds into the pitch’s flight, you have a clue as to what’s coming. The charts above are only against right-handed hitters, but the pattern is similar for lefties.
For a long time, Wainwright’s curve was so great it didn’t matter if hitters knew when he threw it. That isn’t the case anymore, but it looks like Wainwright is adjusting. Check out his fastball and curveball heatmaps in 2019:
He’s moved his fastball core all the way across the plate to paint the inside corner in the upper-half of the zone and he's throwing his curve for strikes more often. Before, when you recognized a pitch starting high-and-inside, you had a clue that a curveball was coming. Now, it might be a fastball. Both are likely to be strikes, so you have to swing. But which one are you swinging at? You have to guess! What happens when you guess? Sometimes you guess wrong. Hitters are guessing wrong. Take this sequence to Pirates rookie Kevin Newman:
1-2 count, Wainwright sets Newman up with a high-and-tight fastball. Next, Newman sees a pitch on the same plane starting a little more toward the middle of the plate. Based on how quickly he gets his hips through the zone, it looks like he was geared up for an inside fastball. Instead, he barely makes contact with a pitch that ends in the opposite corner of the zone. The result is a routine groundout to the third baseman.
Grounders are a good result for pitchers, especially ones hit softly off the end of the bat, and at-bats ending like Newman’s are becoming more common for Waino. The ground ball rate against his curve is up to 55% this season from about 45% in 2016 and 2017. On top of that, those grounders are being hit softer and lower, as evidenced by a jump in how many are considered “topped” or “weak.” A swing-and-miss is the best result, but a soft grounder isn’t a bad one.
The tradeoff has been that the new curve isn’t a standout at generating whiffs (in fact, it’s below average at it). Despite those lackluster metrics, it can still get the job done when executed well. Take this three-pitch sequence to another Pirate, Bryan Reynolds, starting with a 3-0 fastball:
The outside corner in this series was… generous. Reynolds is reminded that he needs to watch out for that corner, and now he knows Wainwright can put his fastball there. Next:
That sure looks like a swing you’d take at a 3-1 fastball over the heart of the plate. The pitch starts out looking almost exactly like the fastball that preceded it. But this one wasn’t a fastball and Reynolds swung at what could’ve been ball four (pitchcast had it barely clipping the zone). Now, the 3-2 offering:
Doesn’t look like a swing I’d take if I knew what was coming. It doesn’t look like the swing Reynolds just took when he thought he knew what was coming, either. You can see why: out of the hand, the fastball (green) and curveball (pink) flights look almost identical.
Uncertainty can lead to swings like Reynolds’, but it can also lead to batters not swinging at pitches they should have. Exactly 23% of Wainwright’s curveballs are resulting in a called strike this year, which would be a career high. His called strike rate on fourseamers is up 40% from 2017 and the swing rate against his fourseamers in the zone is near a career low. Considering he allows batters to slug near .500 (or higher) when they swing at either pitch in the strike zone, reducing the frequency of those swings is a key to limiting the potential for damage.
For good measure, lest you think we only pick on Pirates, check out this sequence to Marcus Semien:
This is a 91 mph fastball to a location where Semien is slugging .624 since the 2015 season (even on the black). It would have been right in his wheelhouse had he recognized fastball out of the hand. He didn’t, so he turned back to sit down.
Entering 2019, Adam Wainwright seemed so far done that he received only $2 million guaranteed as part of an incentive-laden “Prove It” deal. Riding a retooled curveball and crafty location adjustments, he’s proven it.
Edit: Credit to @cardinalsgifs for his incredible work (and patience) that went into this analysis. I am a verifiable moron for leaving out his credit the first time.