Nathan Eovaldi and the ace that never was


A lot comes to mind when one hears the name Nathan Eovaldi. Among the positives include his well above-average velocity, good control (after years of improvements), and ability to limit home runs. Some of the negatives include his lackluster strikeout rates and command and secondary pitches that seem to lag behind, especially compared to his fastball. While pitchers do tend to take some time to develop even after reaching the big leagues and should be given something of a grace period, Eovaldi’s pedigree and big fastball placed quite a bit of pressure on him to perform at a very high level almost immediately after being placed into the Miami Marlins rotation.

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Ultimately the Marlins decided he was something of an expendable piece, or at least one that wasn’t untouchable, and he was dealt in a trade package that netted the team Martin Prado and David Phelps. It was a fine deal: the Marlins filled a need at third base and despite advanced stats like FIP rating him as an above average starting pitcher, Eovaldi never quite reached his ceiling in his brief tenure with the team.

Was Eovaldi’s performance really disappointing enough to move him instead of another one of his rotation mates? First of all, his 2014 wasn’t as bad of a season as many would believe. Much of Eovaldi’s plate discipline stats were identical, save for a 3% increase in first pitch strike % (which correlates with walk rates). This explains his much improved BB% that sat comfortably below average last season. His groundball % and home run/fly ball rate were also virtually instep with his career averages.

The two differences that stick out are his BABIP, which was nearly 40 points higher than in 2013, and his left on base %, which was 8 points lower than the previous year’s mark. These numbers suggest Eovaldi faced quite a bit of bad luck, which inflated his ERA so much that it was a full run higher than his FIP.

However, even factoring out the bad luck Eovaldi suffered through, his performance still falls short of that high ceiling one would expect given the talent he possesses. As I outlined above, Eovaldi has done some things well and has done some things not as well as many had hoped. I believe all of these are connected by one thing: how Eovaldi pitches with his fastball. Almost all of the time, pitchers use their fastball to set up the rest of their pitches. With a pitcher like Eovaldi, whose fastball velocity is obviously superb, this is even more true.

Throughout his entire career, Eovaldi has pitched low with his fastball. Despite possessing the 4th-highest average fastball velocity last season at 95.5 mph among qualifying starting pitchers (.1 mph behind 3rd place Wily Peralta), Eovaldi ranked 63rd in vertical fastball movement with an average vertical movement of 8 inches, or about a full inch lower than average. His career average is 7.5 inches, which is bumped up a bit by his 2014 season (all of this info is thanks to PITCHf/x and can be easily observed here.) Basically, Eovaldi has combined the power fastball of a pitcher you would expect to rack up strikeouts with the approach of a pitcher that might focus more on putting the ball in play and generating groundballs, but certainly not to any extreme. These are two very different profiles of starting pitchers.

This is also reflected in his heat maps. Since joining the Marlins, Eovaldi has focused more and more on pounding the bottom part of the strikezone, which seems to be something of an organizational philosophy. However, this has placed a cap on Eovaldi’s potential. Fastballs pitched low in the zone have higher contact rates, while of course having higher groundball rates. Fastballs pitched up in the zone have lower contact rates, but higher fly ball rates. Fly balls, of course, have the potential to be home runs. Eovaldi has limited home runs very well to this point in his career, so there may be some hesitation to suggest he change his approach. However, pitchers that generate a below-average rate of groundballs (pitchers that pitch up in the zone with their fastballs) are actually better at managing flyball contact. They post lower home run/fly ball rates and higher infield flyball rates than average and high groundball percentage pitchers.

All of this suggests the Marlins, as well as the Dodgers, were unnecessarily limiting Nathan Eovaldi. Fastball velocity correlates with strikeouts, but when the pitcher’s approach resembles one closer to a groundball pitcher that prioritizes generating groundballs, there aren’t really many opportunities to make hitters swing and miss. Pitch up in the zone, however, and hitters will swing and miss much more often. Eovaldi has a very large margin of error in the upper portion of the strikezone considering his incredible velocity (seriously, it’s very good.)

He should be blowing hitters away with that velocity rather than posting contact and swinging strike rates that are well worse than average. For his career, his fastball swinging strike and contact rates are 6.4 and 87%, respectively. League average rates (on all pitches) last season were 9.4 and 79.4%. Even worse, Eovaldi’s rates in 2014 on his fastball were 5.5 and 89.2%. These numbers are very meaningful. Eovaldi’s fastball should be his best strikeout weapon but given how he uses it, it’s basically become a pitch he uses to generate contact on. This is a major reason why his strikeout rates are much lower than expected.

But this also bleeds over into pitch sequencing. A big reason why Eovaldi’s secondary pitches have failed to develop is most likely because of how they are being set up. He lives low and away, especially against right handed hitters. He seems to fall into a very predictable pattern of pounding that portion of the strikezone with his fastball then trying to get hitters to chase his slider low and off the plate. That is not going to fool big league hitters and they’ll just spit on those sliders in the dirt. Even if Eovaldi learns how to elevate his fastball more to set up his slider, it would make it a much more effective pitch. Eovaldi’s command of his slider might still need some work, but it could become a knockout pitch even if he just learns how to set it up better.

Now, this isn’t to say that Eovaldi hasn’t been a good pitcher in his career. If he keeps pitching the way he has, he’ll have a good career and might make an All-Star team or two. However, many have been waiting for Eovaldi to take that step and join the next tier of starting pitchers or maybe even become a true ace. Eovalid has a great fastball that should help him rack up tons of strikeouts, but his approach, whoever it was instilled by, has limited him so far. No doubt pumping fastballs up in the zone would not only allow it to become a better strikeout pitch, but it should allow his other pitches to be much more effective.

Most importantly, those strikeouts would not come at the expense of his ability to limit walks and home runs. Eovaldi’s control has really taken a big step forward, with his BB% ranking 21st last season (tied with Felix Hernandez). That is a skill that will not change with a different approach. A change in approach might actually allow Eovaldi to suppress home runs even more, since a 96 mph fastball up in the zone would be extremely difficult to square up even for the Miguel Cabreras of the world (well okay, there’s only one of those.)

It seems like a very simple adjustment — and it is — but it’s definitely one that can go a long way towards unlocking that last bit of potential Eovalid has within him.

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