Despite flashing top notch stuff, Zack Wheeler struggles with the command and the consistency of his pitches. It’s the reason why Wheeler is currently only an average pitcher, and it’s the single biggest force holding him back from achieving his high ceiling. Baseball Prospectus labeled Wheeler’s ceiling as a "1" prior to 2013, which is enormously high praise. There aren’t many true "1"s in the sport; Kevin Goldstein used to say that you could count "1s" on your own hands because there are so few in the game.

Here’s what Baseball Prospectus had to say about Wheeler prior to 2013:

At some point during the season, Wheeler will arrive in New York and become one of the brightest stars in town, thanks to a fastball that can sit in the mid-90s and approach elite velocity, a curveball that has the bite to buckle the best hitters in the game, a slider that plays well off the fastball and forces weak contact and a changeup that should be able to keep lefties honest. Wheeler has a chance to become the most electric arm in Flushing since the Doc, which sounds like hype and hyperbole but could end up being the honest truth.

For Wheeler, a combination of throwing more first pitch strikes with his fastball and improving fastball location will help bridge the gap between average pitcher and star.

Career overview

Despite a decrease in run prevention, Zack Wheeler made strong progress from his rookie season in 2013 to 2014. His Fielding Independent Pitching, strikeout rate, ground ball rate, fly ball rate and swinging strike rate all improved significantly, while moderately improving his walk rate. Statistics like these are more important to look at for future ERA than past ERA, so despite a higher ERA, Wheeler had a better process on the mound than he did in his rookie season.

Here’s a look at some notable statistics:

Table 1

Year ERA ERA- FIP FIP- xFIP 2013 3.42 96 4.17 117 4.21 2014 3.54 102 3.55 101 3.49

Table 2

Year K% BB% SwStr% GB% FB% 2013 19.5% 10.7% 8.8% 43.2% 33.3% 2014 23.6% 10.0% 9.8% 54.0% 27.3%

For reference, the NL averages in 2014 for these statistics are posted at the bottom of the article.

Interestingly, Wheeler got significantly more swinging strikes as the 2014 season went on. This could be completely arbitrary, or there could be something behind it:

Months SwStr% IP April-May 8.6% 62.2 June-end 10.5% 122.2

Wheeler’s swinging strike rate from April to May was essentially the same as it was in 2013 before jumping up significantly. It’s possible that Wheeler made an adjustment, either through natural progression or by design, around June that caused him to miss more bats.

Something I noticed watching Wheeler during the season is that he began locating his curve much better starting in his May 29 start against the Phillies. This could explain the rise in missed bats. Again, it could be arbitrary, but it's something to keep an eye on for 2015.

Platoon splits

Wheeler has large platoon splits for his career. He was fantastic against righties in 2014, but lefties give him problems.

Against RHB:

Year K% BB% FIP OPP. OPS GB% FB% 2013 19.7% 6.4% 3.58 .639 48.2% 28.9% 2014 26.0% 7.1% 2.99 .616 63.5% 22.0%

Wheeler has a career BB% against RHB of 6.9%, which is above MLB average.

Wheeler’s walk issues stem from his problems against LHB. He has gigantic walk rate platoon splits against lefties.

Against LHB:

Year K% BB% FIP OPP. OPS GB% FB% 2013 19.2% 15.7% 4.94 .766 36.7% 39.1% 2014 21.0% 13.0% 4.21 .745 44.2% 32.7%

That adds up to a career BB% of 13.9% against LHB, which FanGraphs classifies as beyond "awful". These walk rate platoon splits are extreme.

A big key for Wheeler in 2015 will be reducing his walk rate against LHB.

Tom Seaver: The best pitch is strike one

Mets legend Tom Seaver has a famous quote. When asked what his best pitch was, Seaver answered, "strike one".

Daniel Wexler (@WexlerRules) noted that Zack Wheeler was last in MLB in first pitch strikes in 2014 at 54.4%. According to FanGraphs, MLB average first pitch strike in 2014 was 60.6%.

Pitchers have much better results after they get ahead 0-1 in the count. Wheeler’s results were dramatically different in 2014 once he got to 0-1 in the count, via FanGraphs:

Count FIP K% BB% OPP. OPS WHIP Thru 0-1 2.24 31.9% 5.7% .518 0.89 Thru 1-0 4.81 19.4% 16.1% .800 1.92

Here’s a split between Wheeler ahead in the count, even and behind in the count, via Baseball Reference:

Count AVG OBP SLG OPP. OPS Ahead .155 .165 .202 .367 Even .286 .298 .456 .755 Behind .279 .472 .396 .869

By executing Seaver's approach of prioritizing first pitch strikes, Wheeler will see his results improve significantly.

According to some research, there is not a whole lot of risk in pounding the strike zone on the first pitch of the at bat, either. In an article written by Craig Burley of The Hardball Times, Burley states that a shockingly low amount of first pitch strikes turn into hits:

The figure for 2003, as I calculated from some wonderful data provided by Tom Tippett at the Diamond Mind Weblog, is 7.3%. Those figures do not include pitchers hitting; presumably if you throw in the pitchers as well it would be a couple tenths of a percent worse for the hitters. That’s just shocking. 92.7% of the time, if you throw a strike to the opposing hitter, you get either a 0-1 count or an out.

Joe Maddon’s Rays teams thrived on fastball command and a first pitch fastball strike approach

Joe Maddon and Andrew Friedman’s Rays, who enjoyed massive success under their limited resources, preached fastball command and first pitch fastball strikes to their pitchers as a key component of success. Adam Berry of MLB.com wrote,

The Rays preach the importance of a fastball-first repertoire and fastball command as much as any organization in the Majors. It's how they've developed an incredible number of young pitchers, from the four homegrown starters in their current rotation -- David Price, Jeremy Hellickson, Matt Moore and Alex Cobb -- to the ones they've traded away, like Royals ace James Shields. With so many members of the Rays' staff featuring an arsenal of fastball, changeup and curveball, everything has to play off the heater. For the most part, breaking balls start off in the strike zone then end up as balls. Hypothetically, a disciplined hitter should have the sense to lay off those offerings and force the pitcher to throw strikes. That's why the Rays teach their pitchers to rely on their fastballs to quickly get ahead in the count and set up their offspeed pitches to get outs, whether it's by strikeout or by inducing weak contact.

Nationals 3B Ryan Zimmerman said,

"A well-located fastball is still the hardest pitch to hit in the big leagues. I think some people forget that sometimes."

Joe Maddon agrees.

"Absolutely, no question…and that's how you get quick outs. The group that goes away from that, it boggles my mind. They don't understand that concept."

"Unless you can throw your fastball where you want it and when you want it, the other pitches almost become moot. And if you choose to throw those other pitches all the time, you're probably going to get hurt." "I believe the most successful pitchers that pitch a long period of time pitch with their fastball first, and then everything plays off of that. I think the fastball pitchers with command and aggressiveness pitch deeper into games. That's why those are the guys that are in the seventh and eighth inning with decent pitch counts."

Wheeler is the perfect pitcher to execute this approach because his fastball is so good. It's explosive, it has movement, it's thrown on a downward plane, it generates a high GB%, and it's thrown with some deception.

Wheeler only made it through 7 IP twice in 2014. He often worked up high pitch counts and was forced to exit games early. Executing Maddon's blueprint of getting ahead with aggressive fastball use will not only help Wheeler become a more effective pitcher but a much more efficient pitcher.

Matt Harvey: Hitters become a lot better when you're behind in the count

Teammate Matt Harvey shed light on the importance of being aggressive, getting ahead in the count and trusting your stuff. Andy Martino of the New York Daily news wrote,

In his first few major league appearances, Harvey was surprised to see the quality of opponents’ swings when he fell behind in the count; that spooked him, so he made a point to be more aggressive earlier in at-bats. "They become really good hitters, a lot better hitters, when you are behind," Harvey said. "You learn that quickly. When you go 2-0 on a guy and see the hacks that he takes, I’d rather be 0-2 or 1-2. You remember those swings." Still, Harvey needed experience, and innings, to hone his command -- it was far less consistent last season than in the first half of this year. "It’s experience," he said. "It’s knowing yourself, and trusting yourself. That was it for me, trusting my stuff. Obviously there was some mechanical stuff that needed to be done, whether it was staying back a little longer, minor adjustments like that. It was just little things that I needed to learn and change. Once I was able to do that, I was able to pound the zone a lot more."

Visuals: Delivery

Wheeler has some deception in his delivery because he hides the ball behind his shoulder as he’s delivering the ball to home plate. This makes his fastball explode on hitters and jump on them quickly.

Notice below how Wheeler keeps his front shoulder tucked high, tight and closed as he’s striding towards home plate. Some pitchers let their front shoulder fly open as they stride to home plate which makes it easier for batters to see the ball.

It’s a small detail, but it makes a big difference.

Repertoire

Here’s a chart of Wheeler’s pitch types by year, via FanGraphs:

Year Four seam Two seam Curve Slider Change 2013 51.2% 20.3% 9.4% 16.4% 2.4% 2014 44.2% 22.1% 15.7% 14.3% 3.5%

Wheeler’s increased use and increased comfort with his curve may explain his rise in swinging strike rate in 2014.

Four seam fastball

Zack Wheeler boasts one of the hardest fastballs in baseball. According to FanGraphs, Wheeler’s average four seam fastball velocity in 2014 was 94.7 mph, sixth highest in baseball.

Here’s one of the best fastballs Wheeler threw all season. This pitch is 98 mph, located down in the zone with late heavy sink.

It is also 72 pitches deep into the game. In 2013, Wheeler lost velocity as the game progressed, but in 2014, Wheeler largely held his velocity through the game.

What is also impressive is how easy Wheeler’s velocity comes. There isn’t much effort in his delivery.

Ground balls

Wheeler generates a strong amount of ground balls on his four seam fastball (49.5%). A large part of this is because it often shows late, downward movement. Wheeler also throws the ball on a nice downward plane.

Here’s an example of Wheeler generating a weak ground ball on a 97 mph four seamer:

Pay close attention to the late, hard sink, which causes the ball to hit the bottom of the barrel, generating forward spin. Pitchers want to generate forward spin on batted balls because forward spin causes the ball to dive into the ground.

Because Wheeler generates such a strong GB%, he can eliminate some of his walks via the double play. Here’s a sinking fastball down in the zone that generates a weak ground ball for a double play:

The combination of Wheeler’s hard velocity, hiding of the ball and late sink is why he generates such a high percentages of ground balls on his four seam fastball.

Swing and miss

Wheeler generates a strong swinging strike rate on his four seamer. According to FanGraphs, the average swinging strike rate on a four seam fastball is around 6.9%. Wheeler’s was 9.1%.

Here’s Wheeler blowing a 97 mph fastball past Justin Upton:

The .gif above is also a good look at the downward plane Wheeler can generate on his fastball.

Here's a 97 mph inside fastball that ties up LHB Domonic Brown:

Here's 96 mph sinking fastball that strikes out Ryan Doumit:

Pitch type OPP. wRC+ OPP. OPS SwStr% GB% FB% 4 seam FB 119 .719 9.1% 49.5% 26.4%

Two seamer

Wheeler's average 2 seam velocity was 94.5 mph, 7th best in baseball. The pitch limits fly balls a little better than his four seamer and generates a similar ground ball percentage.

Here’s a double play turned on a 95 mph two seamer:

Pitch type OPP. wRC+ OPP. OPS SwStr% GB% FB% 2 seam FB 130 .765 8.1% 50.8% 21.7%

Well located fastball

When Wheeler locates his fastball well, he’s lethal. Here’s Wheeler painting a 97 mph fastball on the outside corner to strike out Bryce Harper:

Curve

Wheeler possesses a knockout curve. The curve was by far his best pitch by wRC+ against and OPS against in 2014. It moves differently at times; it shows both two plane movement and primarily vertical drop.

Two plane break

Here’s a hellacious 80 mph two plane breaking curve thrown to Giancarlo Stanton:

Here’s another example of a two plane breaking curve:

Primarily vertical drop

Here's Wheeler making Anthony Rendon look foolish on an 81 mph vertically dropping curve:

Wheeler making Freedie Freeman swing and miss on an 82 mph curve:

Wheeler’s curve will be a key piece in improving his platoon splits against LHB.

Pitch type OPP. wRC+ OPP. OPS SwStr% GB% FB% Curve 31 .432 14.1% 66.7% 18.3%

Slider

Wheeler flashes a fantastic slider. Wheeler’s best slider is thrown in the low 90s with tremendous break.

Here’s a 91 mph slider with ridiculous break:

Here’s a ferocious 92 mph slider:

Wheeler’s slider is so nasty at times, but it’s inconsistent. At times it flattens out and looks more like a cutter. When Wheeler’s slider flattens out, hitters make far better contact against the pitch.

Wheeler commented on his slider inconsistency during the 2014 season:

"My slider was terrible — it hasn’t been good the last few starts," Wheeler said after the Mets’ 1-0 loss to the Marlins. "I think I’m on the side of the ball, so it’s bigger than I want it to be and I don’t have that good command of it."

Wheeler can get away with some hanging sliders due to the velocity of the pitch.

Pitch type OPP. wRC+ OPP. OPS SwStr% GB% FB% Slider 92 .638 12.7% 61.2% 14.1%

Change up

Wheeler doesn’t throw his change up much (3.5%). The pitch is inconsistent, but it flashes signs of being an effective pitch.

Here’s a good 3-2 change up to get a swinging strikeout of Giancarlo Stanton:

Here’s another good change up that runs back to arm side at 89 mph against Jason Heyward, generating a weak grounder. Heyward’s bat made a really ugly sound after hitting the pitch:

Here’s a change up that generates a swinging strikeout of Derek Dietrich:

Pitch type OPP. wRC+ OPP. OPS SwStr% GB% FB% Change Up 124 .732 7.0% 50.0% 31.3%

By improving the consistency of his change up, he can add another weapon against LHB.

Hard hit rate

Wheeler was not easy to square up in 2014. He had the 32nd best hard hit rate amongst starting pitchers at 13.6%, ahead of notable pitchers like Corey Kluber and Stephen Strasburg. Wheeler's velocity, movement and deception are key factors in this.

Final Thoughts

The theme for Zack Wheeler in 2015 is aggressive fastball use in the strike zone to get ahead of hitters. Wheeler’s fastball is so good that it is tough to square up even when it isn’t located well, and the pitch generates ground balls at a near 50% rate.

Wheeler could fall victim to a subpar Mets infield on his ground balls, but I think some of these problems are overstated. Wilmer Flores had a terrible defensive reputation at SS in the minor leagues, but he looked surprisingly competent defensively last season at SS. He has good hands and a strong arm and will make the routine plays. Flores is also capable of making some fantastic plays, like here:

His defensive metrics graded him well at the position (although in such a small sample size, DEF metrics need to be taken with a huge grain of salt).

Wheeler has the tools to dominate the National League if he can iron out his command issues. We've seen many examples of young pitchers struggle with command and eventually develop strong command. One prime example is teammate Matt Harvey. Like Wheeler, Harvey would often work up large pitch counts due to shaky command and would be forced to exit games early. A switch went off in Harvey's age 24 season and he lowered his walk rate from over 10% in 2012 to 4.5% in 2013, showcasing newly acquired outstanding command of his pitches.

Maybe Wheeler can make a similar progression in 2015.

Average statistics for reference:

2014 National League averages, via FanGraphs:

ERA ERA- FIP FIP- xFIP 3.66 100 3.69 100 3.67

K% BB% SwStr% GB% FB% 20.5% 7.6% 9.6% 46.0% 33.2%

Pitch type benchmarks, via Eno Sarris:

Swinging strike:

Pitch type SwStr% 4 seam 6.9% 2 seam 5.4% Curve 11.1% Slider 15.2% Change up 14.9% Cutter 9.7%

GB%:

Pitch type GB% 4 seam 37.9% 2 seam 49.5% Curve 48.7% Slider 43.9% Change up 47.8% Cutter 43.0%

. . .

Follow Tim on twitter at @TimFinn521