In 2018, after the All-Star Game, Zack Wheeler went 9-1 with a 1.68 ERA. He had 73 strikeouts in 75 innings and had a 0.81 WHIP. His 1.68 ERA was the lowest in the majors after the All-Star game. Zack Wheeler actually pitched better than teammate, and CY Young award winner Jacob DeGrom in the second half of the season. But before that Wheeler made a total of just 35 starts in 4 seasons.

Zach Wheelers 2018 pre and post All-Star Game Splits

Acquired by the Mets from the Giants in the 2011 season for Carlos Beltran, Wheeler was a highly regarded prospect who quickly rose through the minors. Before there was Jacob DeGrom and Noah Syndergaard, the original plan was to have a one-two punch of Matt Harvey and Zack Wheeler. At the beginning of the 2013 season, Wheeler was ranked 6th on MLB.com’s Top 100 Prospects list. On June 18, 2013, Zack Wheeler made his major league debut against the Atlanta Braves, an hour away from where he grew up in Georgia. In his first two seasons, Wheeler went 18-16 with a 3.50 ERA in 49 starts. He had a 2.6 fWAR in his first full season in 2014, but then things went bad…

On March 16th,2015, Zack Wheeler was diagnosed with a torn ulnar collateral ligament. On March 25th, Wheeler underwent Tommy John surgery to repair his UCL and missed the entire 2015 campaign. Wheeler began 2016 on the 60-day DL and did not start rehabbing until August 6th. On August 16th, Wheeler was shut down for 2 weeks and then on September 3rd, Wheeler was shut down for the entire season. After missing two entire seasons, Wheeler was ready to return to the Mets in 2017. Wheeler did make 17 starts for the Mets in 2017, but found himself on the disabled list twice and shut down for the season in late August after throwing only 86 innings.

Wheeler was a long way removed from being a top prospect when the 2018 season began but he was finally healthy. Unfortunately, the Mets signed Jason Vargas, who was an All-Star in 2017, to compete with Wheeler for the 5th spot. Wheeler pitched poorly in Spring Training and was optioned to AAA to start the 2018 season. At this point in the season, ZIPS projected that Jason Vargas would be more valuable than Wheeler and it would have been valid due to Wheeler never producing up to his hype. By the time Wheeler would finish the season, he would have a 4.1 fWAR, 15th-best among pitchers in all of baseball for 2018, and a second half season that was better than Jacob DeGrom’s. So, what exactly changed?

Zack Wheeler changed his approach from the 2017 season to the 2018 season and it finally started to breakthrough around the All-Star break. To start, Zack Wheeler changed his trainer, diet, and received injections after the 2017 season to strengthen his bones. Already on the right track to avoid injury, Wheeler went even further and changed his pitching approach to ensure success.

Below is a side by side comparison of Zack from his debut in 2013 to 2018.

Zack Wheeler’s mechanics from his first start on June 18th, 2013

Zack Wheeler’s current 2018 mechanics



Notice how Wheeler has a much lower release point and doesn’t stand up as tall in the second GIF, I’ll touch upon that later.

In 2017 one of the biggest causes for Zack Wheeler’s misfortunes was his sinker, which he threw 20.4% of the time according to BaseballSavant. According to FanGraphs, Wheeler’s sinker was in the bottom 10 of all sinkers in baseball. Wheeler also did not utilize his change-up enough in 2017, only throwing it 4.7% of the time. In the 2018 season, Wheeler was able to throw both pitches more effectively. Zack Wheeler modified his sinker to throw more of a split-finger fastball instead. He limited the use of this split-finger/sinker to only 6% and was able to use it more effectively cutting down on base hits allowed from the split-finger/sinker and increasing swing and misses. The split-finger was much more successful than his sinker from 2017. Batters only hit 0.199 against Wheeler’s 169 splitters in 2018. Wheeler also changed the gripping on his change-up to limit what Travis d’Arnaud called “overthrowing it.” The grip is much looser now and not only is usage up to 12.5%, swing and misses on the pitch are also up significantly. The use of this change-up was instantly effective. Opposing batters spotted a .255 average in 2018 against Wheeler’s change-up, a career low for him, down from .474 from 2017. According to BrooksBaseball, right-handed hitters hit 0.033 against Wheeler’s change-up in 2018. Wheeler was also able to find excellent command of his main pitch, the fastball, which he increased usage up to 58% in 2018.

Overlay of Wheeler’s Curveball and Fastball from PitcherList

Even after Tommy John surgery Wheeler is throwing his pitches harder than he ever has before. The velocity on each one of his “top-3 hard pitches by usage” was up at least 0.5 MPH from 2017 to 2018 including an increase in 3 MPH on his slider. The data below courtesy of BrooksBaseball shows the increase in Wheeler’s velocity on each of his pitches from 2017 to 2018.

Pitch 2017 Velocity 2018 Velocity Fastball 95.5 96.5 Slider 88.6 91.4 Change-Up 88.8 89.3

One of the biggest keys to a successful pitcher is strikeout a lot of batters and walk a very few batters. Wheeler increased in both of those categories this past season. Wheeler’s strikeout rate for 2018 was 24%, the 24th highest in all of baseball. Zack’s walk rate was a career low of 7.7%. A majority of this is from the fact that Wheeler changed his release point which gave him better command of his pitches as well as changed the movement of his pitches. Wheeler was able to cut down the rise of his fastball, giving him more command and reduction on the hang of his slider by almost an inch and a half. In 2018, Wheeler was able to complete at least six innings 23 times in his 29 starts; in 2017, he only made it to the 7th inning twice. Wheeler’s increased durability, stamina, and pitching adjustments are allowing him to get deeper into games and he is able to get deeper into his games because his variety of effective pitches used correctly are constantly making hitters guess at the plate.

As you can see from the charts below (taken from BrooksBaseball), Wheeler lowered both his horizontal and vertical release point on all of his pitches from 2017 to 2018.

Zach Wheeler lowered his horizontal release point on all pitches from 2017 to 2018

Zach Wheeler lowered his vertical release point on all pitches from 2017 to 2018

Zack Wheeler’s 2019 projections are very scattered. From Fangraphs, to Baseball Prospectus’ PECOTA projections, to Steamer and Depth Chart, Wheeler is projected to finish roughly in the 2.5-3.0 WAR range. His win total is projected to be around 10-12, and his ERA has been anywhere from 3.17 (Fans) to 3.85 (Depth Chart and Streamer). Wheeler’s second-half of 2018 is why I believe he can exceed those projections and be not only the key to the Mets 2019 success, but also a dark-horse CY Young candidate.

The Mets have an already amazing 1-2 punch in deGrom and Syndergaard and is one of the best in baseball. deGrom is a given to return to his success and Noah will have no problem if he can stay healthy, which I believe he can. That leaves Zack Wheeler, and we have to hope his post-All-Star 2018 wasn’t a flash in the pan and truly was Wheeler living up to his potential. The New York Mets are rivaled in the division by a rotation of Max Scherzer, Patrick Corbin, and Stephen Strasburg. DeGrom can be better than Scherzer as shown by his 2018 season, and Syndergaard can be better than Corbin if fully healthy. In 2018, Zack Wheeler posted a 24.8% hard hit ball rate, one of best in the MLB, and that is the key to all of his success. Combine that hard hit % rate with his opponent’s average exit velocity, which was 84 MPH, top 3 in the league, and it’s lethal. Strasburg had a 38.9% hard hit rate in 2018, 252nd in baseball for reference. If Wheeler can keep opponents from squaring up on the ball, he will have no problem being up in the category of the top twenty pitchers in baseball. Syndergaard and deGrom were also top five in hard hit ball rate in 2018, and if that continues in 2019, the Mets three-headed monster will do very well.

Graph Shows The drop in Wheeler’s Hard Hit % from 2017 to 2018

Wheeler’s second half is nearly impossible to replicate, on average, I expect his 2019 stat line to look something like the following: 30 GS, 180 IP, 15 W, 3.50 ERA, 3.80 FIP, 1.20 WHIP, 9.00 K/9, and 3.00 BB/9, and a .289 BABIP (data was averaged from various projections). The minimum needed from Wheeler is 15+ wins, close to 200 IP and a sub 3.50 ERA. If he can do this, the Mets will seriously challenge for that National League East title. If Wheeler is able to keep that hard-hit rate low, equivalent to his 2018 percentage then his numbers should get a boost that can make him the 2B to Noah Syndergaard’s 2A and make the Mets have an unstoppable 1-2-3 punch. If they can establish this consistent 1-2-3 punch, they will be competitive in every series they play in 2019. However, if Wheeler is not able to replicate his second half of 2018 and returns to his 2017 form, then were looking at a 4.50-5.00 ERA with a lot of balls leaving the ballpark and more games lost than won. If Wheeler produces above his expectation, which he is certainly capable of, it could give the Mets those extra three wins needed to surpass the Nationals and their 89-game win projection. If Wheeler cannot, those extra losses might knock the Mets out of the Wild-Card spot they are currently in.

There is a lot riding on this season for Zack Wheeler as well. He is in a contract year. He was worth roughly $12 million in 2018 and is projected anywhere from $7.5 million to $9.8 million in 2019. If I were the Mets, I would 100% lock him up now while his value is low. If he has another season like 2018, I can see his value skyrocket to around $15-18 million per year and this might be out of the Mets price range. While this does put a lot of pressure on Zack, it also ups the incentive for him to make this season his best yet if he wants to be paid big this offseason.

I have seen Zack Wheeler in person since he came up, and he looked like a completely different pitcher in 2018. I have always been on the Wheeler hype-train since he was a prospect, but I am finally willing to make the investment on him and I think the Mets should too.

Featured Image by UCInternational from Flickr