Deep Dive: Zack Wheeler

Frank Ammirante  | June 27th, 2019

Zack Wheeler was one of the more hyped starting pitchers coming into the 2019 season. He has electric stuff and he absolutely dominated hitters down the stretch.

Last 10 Starts of 2018:

68.0 IP, 1.59 ERA, 0.82 WHIP, 5.5 BB%, 27.3 K%

Many believed that Wheeler would take the next step to become a bonafide ace, but he has struggled this season. Let’s take a deep dive into the numbers.

Surface Stats

2018: 3.31 ERA, 1.12 WHIP, 7.4 BB%, 24.1 K%, 16.7 K-BB%, 10.7 SwStr%

2019: 4.69 ERA, 1.30 WHIP, 6.7 BB%, 24.8 K%, 18.2 K-BB%, 10.7 SwStr%

Here we see that Wheeler has maintained his strong control and strikeout abilities. His BB%, K%, and SwStr% have either improved or remained the same. This is encouraging because it demonstrates that his stuff has not declined.

Pitch Velocity (MPH) & Usage (%)

Fastball (FB), Splitter (SP), Curveball (CV), Slider (SL), Sinker (SI)

2018: FB (95.8, 42.3%), SL (90.8, 19.3%), SI (96.0, 15.2%), SP (89.3, 11.8%), CV (79.3, 10.5%)

2019: SI (96.7, 31.1%), FB (96.9, 26.8%), SP (89.2, 12.9%), CV (81.1, 11.7%), SL (91.7, 71.5%)

Wheeler has maintained his high velocity, but he has increased the use of his sinker at the expense of his fastball. Let’s delve into this further to see why Wheeler has gotten away from this pitch.

Pitch Value

Whiff% (W%)

2018: FB (9.0 BB%, 23.9 W%, .298 wOBA), SL (5.1 BB%, 27.1 W%, .245 wOBA),

SI (4.2 BB%, 15.1 W%, .245 wOBA), SP (7.1 BB%, 29.4 W%, .282 wOBA)

CV (9.1 BB%, 38.6 W%, .247 wOBA)

2019: FB (13.2 BB%, 28.1 W%, .298 wOBA), SL (5.2 BB%, 25.9 W%, .350 wOBA),

SI (4.5 BB%, 18.8 W%, .318 wOBA), SP (3.0 BB%, 18.6 W%, .261 wOBA)

CV (4.9 BB%, 24.7 W%, .279 wOBA)

Wheeler has struggled to locate his fastball this season, which has led him into unfavorable counts and allowed hitters to lay off his secondary pitches. This is why his fastball usage has decreased. It also explains why his slider and curveball have been much less effective this season.

Plate Discipline

2018: 28.8 1st-Pitch Swing%, 67.2 Zone Swing%, 62.3 Chase Contact%, 24.8 Whiff% 

2019: 35.2 1st-Pitch Swing%, 70.8 Zone Swing%, 66.5 Chase Contact%, 22.9 Whiff%

Hitters have been much more aggressive with Wheeler, swinging at the first pitch more often than a year ago. They have also attacked pitches in the strike zone. This aggressive approach has been an effective adjustment and helps explain Wheeler’s current struggles.

Batted Ball Stats

2018: 3.81 xFIP, 3.87 SIERA, .279 BABIP, 74.6 LOB%, 46.1 GB%, 21.6 FB%

2019: 3.90 xFIP, 4.03 SIERA, .314 BABIP, 66.1 LOB%, 44.4 GB%, 21.2 FB%

These stats tell us that Wheeler was a bit lucky last year and a bit unlucky now. He’s stranding fewer runners and more batted balls are falling for hits. It is encouraging to see that his groundball and flyball rates are similar to last year’s totals.

Advanced Batted Ball Stats

Line Drive% (LD%), Weak Contact% (Weak%), Solid Contact% (Solid%), Barrel Contact% (Barrel%), Exit Velocity MPH (EV), Home Run/9 Innings (HR/9), Home Run/Flyball Rate (HR/FB)

2018: 24.0 LD%, 6.4 Weak%, 4.2 Solid%, 4.8 Barrel%, 84.7 EV, 0.69 HR/9, 8.1% HR/FB

2019: 26.9 LD%, 4.4 Weak%, 6.4 Solid%, 7.1 Barrel%, 88.0 EV, 1.24 HR/9, 13.7% HR/FB

Hitters are generating much harder contact on Wheeler’s pitches this season. This further demonstrates how their newly aggressive approach is paying dividends. Wheeler needs to make an adjustment to help induce more weak contact.

Zack Wheeler has the same electric stuff that made him one of the most dominant starters in the 2nd half of the 2018 season. The difference this year is that hitters have adjusted and taken a more aggressive approach, which has led to more hard contact and more extra-base hits. I think that Wheeler should try to throw fewer pitches in the zone to try to get hitters to chase his off-speed pitches. This would be a trade-off that would result in more walks, but fewer extra-base hits.


Buy-low, but expect SP3 numbers, not a fantasy ace

It’s clear that the Wheeler we saw in the 2nd half of the 2018 season was an outlier. He’s still a very good pitcher, but this is not a guy that we can expect to put up ace-like production. Wheeler will likely finish the season strong and is a legitimate buy-low option, but temper your expectations.

Check Out The Other Deep Dives: Lucas Giolito | Rafael Devers | Corey Seager | Eduardo Rodriguez | Amed Rosario | Alex Verdugo | Joey Gallo | Mike Soroka | Christian YelichJustin Smoak| Martin Perez|Marwin Gonzalez|Derek Dietrich|Bryce Harper|Kirby Yates|

Questions and comments?

Follow Us on Twitter @thescorecrow
Follow Us on Reddit at u/TheScorecrow
Follow Us on Facebook at The Scorecrow
Follow Us on Instagram at The Scorecrow
Facebook Group where you can read and post articles at The Scorecrow
Reddit Group where everyone can post without fear of being banned at The Scorecrow

Follow Frank Ammirante on Twitter @FAmmiranteTFJ 

Main Image Credit:  Embed from Getty Images


%d bloggers like this: