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Is This the Best Version of Michael Wacha?

Wacha’s expression says it all.

MLB: St. Louis Cardinals at San Diego Padres Jake Roth-USA TODAY Sports

Writer’s Note: This column was written without detailed knowledge of Wacha’s May 29 start in Milwaukee.

In Michael Wacha’s four starts prior to Tuesday’s battle in Milwaukee, shying away from usage of his four-seam fastball has been the norm. 37 percent usage represents an 11 percent drop from Wacha’s first six starts. The righty has never had a stretch of games in the entirety of his regular season career where his fastball usage stayed below 45 percent in back-to-back starts. Wacha’s fastball usage was below 45 percent for four consecutive starts heading into Tuesday.

This is a different Michael Wacha.

Under a month ago, I broke down a pitcher with a tendency to use his curveball early in counts. Since Wacha’s May 1 start against the White Sox, where he previously maintained 35 percent 0-0 curveball usage, his get-me-over hook percentage has taken an 11 percent hit, no longer a noticeable discrepancy opposing hitters are able to zone in on.

We also had reason to believe Wacha’s changeup was an improved pitch, with context suggesting an increase in the offering’s usage. Instead of concentrating on solely upping the usage of his changeup, he’s had an inclination to use each of his three complimentary pitches more.

Data via BaseballSavant

So why is Wacha now developing an affinity for his non-fastball pitches? It could be because of how they’ve changed from the prior year.


Despite the drop in Wacha’s ground-ball rate, the result of this pitch in 2018 has been a noticeable trend towards grounders. While its velocity is slightly down, the pitch’s horizontal and vertical movement have both increased, likely a factor for the increase from a 3.9 to 7.5 groundball to fly ball rate. Supplanting his fastball usage with this cutter in his recent outings allows him to maintain usage of a harder offering instead of turning purely to his offspeed. His location of the pitch - inside to lefties; outer-third to right-handers - suggests an elevated confidence in the pitch as an early count offering as well. All good signs for a developed aspect of Wacha’s repertoire.


Wacha’s changeup has the most interesting velocity differential from the prior year, falling around 1.5 mph compared to 2017 (where his changeup was the hardest of his career). This has maintained his velocity differential when comparing the pitch to his fastball, which also took a slight hit in velocity this year. We understand a fastball-changeup velocity differential towards the lower end of the standard 7-10 mph window results in more groundballs, but Wacha’s changeup is more of a whiff pitch. Maybe this means the pitch isn’t achieving its full potential, but pitching is so pitcher specific, finding deviation from the norm like this is common. Wacha’s most effective offering leaves hitters with only a .167 slugging percentage against. It’s hard to argue against velocity alteration when his changeup has looked as good as any point in his career.


Pitchers often possess variations of their breaking balls depending on the count - soft early in counts, hard late - but Wacha’s curveball has always been a slower offering compared to a lot of the harder curveballs we’re seeing take over the league. His vertical drop on the pitch is up slightly from 2017, sitting inside the 80th percentile of the league, but the pitch only possesses a 21 percent whiff rate, well below its 30 percent mark from last year. This could be a matter of how Wacha is using the pitch, as mentioned earlier, creating a whiff rate that isn’t fully representative of the pitch’s potential. Regardless of that point, his willingness to alter the usage of the pitch this season bodes well for the fourth pitch in his repertoire outperforming expectations.

On ERA alone, one could argue this Wacha resembles the same arm that tore through the National League during the 2013 postseason. Even breaking down how he is using and manipulating his pitches can bring you closer to buying into this version of Wacha.

But there are some things happening with Wacha that are relatively perplexing.

Photo via BrooksBaseball

Of all three batted balls - groundballs, fly balls, and line drives - the latter, on average, do the most damage, with a wOBA almost double that of fly balls. Preventing them is essential to possessing underlying stats that back up results and Wacha. His overall line drive rate is up over 10 percent this season, with his hard hit rate (per Fangraphs) rising by a similar amount. Squaring up Wacha hasn’t been hard in the early going, which begs the question: should Wacha be turning to his offspeed even more?

Given the effectiveness of his cutter, this may not be the best idea. Is it possible an alteration to more cutter usage at the expense of four-seam could lead to a drop in line drive rate, and an improvement of peripherals? Sure, but that’s where the suggestion’s positives might stop. Worry could emerge for Wacha’s general zone percentage and hitter’s willingness to offer at pitches if he’s sitting on the borders of the zone, as offspeed pitches often do.

While my answer is “no” when considering if this is the best version of Wacha, there are encouraging signs that make his start to 2018 worthy of praise and optimism, even if some regression might be around the corner. Wacha’s changeup looks fantastic and his cutter has become an integral pitch to keeping the ball on the ground. Even his adjustments within the first third of his 2018 campaign suggest a more mature pitcher with the ability to succeed in shouldering 150-plus innings for the third time in his career.

If this isn’t the best version of Wacha, it sure is an encouraging one.

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