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Is Nick Pivetta Actually Having a Breakout Season?

A simple question with a complicated answer

Atlanta Braves v Philadelphia Phillies Photo by Mitchell Leff/Getty Images

We don’t commonly refer to pitchers with a 4.66 ERA as having an “elite” season. We don’t usually think of guys with an ERA north of 5.00 after 50-plus Major League starts as “emerging” or “breaking out.” We don’t think of a 3.66 FIP or ERA+ of 90 as “top-of-the-rotation” material. But Nick Pivetta might just be most, if not all, of those things.

In what’s been an up-and-down season for everyone in the Phillies rotation not named Aaron Nola, Pivetta has quietly been making the strongest case for a spot on the 2019 team and beyond, despite the obvious blemishes.

Naturally, I can’t rest this argument on the back of Pivetta’s ERA or home runs rates, both of which are still sub-par. He’s allowed 21 homers in his 145 innings, contributing to his opponents’ Odubel-ian* .263/.320/.422 line against him.

*Odubel’s line as of this post is .263/.319/.438. It’s a little eerie.

But what gets hidden behind that are some numbers that point toward Pivetta actually being an above-average SP (at worst) despite some Jekyll-and-Hyde tendencies. Even better: Some of these numbers should give Phils fans hope that Pivetta’s 2019 will feature continued improvement.


Pivetta is a power pitcher. His profile is one such that, if all else fails, should make him a more viable bullpen arm than Vince Velasquez would be. As a starter this year, he sits 95-96 with his fastball, and throws a hammer curve that, when he’s got it working, is one of the league’s most effective.

Pivetta’s rung up 172 of the 614 hitters he’s faced so far this season. That K% of 28.0 is 13th among all qualified pitchers, snugly between Luis Severino (28.5) and Mike Foltynewicz (27.8) while edging out Nola (26.6) for the team lead. The only pitchers in the National League with better rates are Cy Young Award contenders: Max Scherzer (34.4), Jacob deGrom (31.3), and Patrick Corbin (also 31.3).


As in, he’s not giving up many of them. There’s a certain brand of “power” pitcher who often racks up high punch-out totals at the expense of extra free passes, but Pivetta avoids falling into that trap. His BB% is just 7.0, a hair behind Nola’s 6.8 and, though it ranks 35th out of 71 currently qualified pitchers, it sits below that group’s median of 7.1.

This is one of Pivetta’s most markedly improved areas, as he’s dropped from a BB% of 9.8 in 2017 to 7.0 this season. It doesn’t yet reach the top tier which the likes of Corey Kluber (3.8) and Justin Verlander (4.6) inhabit, but it’s moving in the right direction.

Strikeouts Without Walks

The difference between those two numbers above (simply and understandably displayed as K%-BB%) tells a lot about how the table is tilted for or against a pitcher in one-on-one matchups that leave fielders out of the equation. Consider Pivetta’s nice, round 21.0 K%-BB% this season; the combination of his high K rate and mitigated BB rate places him 13th in that category, a hair behind AL Cy Young Award contender Blake Snell (21.6) and ahead of a group of pitchers that includes Nola, Zack Greinke, David Price, Jose Berrios, Cole Hamels, and others. His year-over-year improvement of 6.8 ranks seventh among pitchers with 100-plus innings in each of the last two seasons, and yet no pitcher with at least 100 innings and a 4.0-plus K/BB has a higher ERA than Pivetta this season. It doesn’t add up.


Here’s where things start to get a little weird, because Pivetta has, for all intents and purposes, produced a batted ball profile that should lead to better results than he’s had.

Batted Balls

. GB% FB% LD% HR/FB% Soft% Med% Hard%
. GB% FB% LD% HR/FB% Soft% Med% Hard%
Pivetta 45.2 36.0 18.8 15.2 17.6 48.6 33.8
MLB Average 43.2 35.3 21.5 12.8 18.0 46.5 35.5

Pivetta is better than average, nearly across the board. And yet you’ll notice that, despite serving up fly balls right in step with the rest of the league and producing less hard contact, more of those flies are leaving the yard. Unfortunate.

But that’s not all!

Batted Ball Types

Pivetta Ground Balls .344 .361 .344
Line Drives .602 .818 .571
Fly Balls .261 .856 .099
League Average Ground Balls .243 .267 .243
Line Drives .628 .913 .612
Fly Balls .209 .652 .088

Holy crap! So, despite having an average-or-better contact profile, Pivetta is getting absolutely torched on ground balls and fly balls, offset only a little by better-than-average line drive luck.

Putting the above into further context, let’s roughly translate Pivetta’s stats to those of a pitcher with a league average BABIP on ground and fly balls. On grounders, Pivetta has allowed 18 more hits than an average pitcher (62 in 180 chances, per Baseball-Reference’s splits). He’s only allowed one more fly ball in play than average (9 in 91), but has had four more fly balls leave the yard for a homer than the league average would suggest.

In fact, if you look at Statcast’s “expected” numbers, which the league derives based on its hit probability calculations (which can’t be counted on to be predictive, but can provide a descriptive angle even if it, too, is a bit incomplete in its current state), Pivetta’s season continues to look like a case of a whole lot of breaks not going his way.

Pivetta’s “Expected” Stats

Pitch Pitch% BA xBA Diff. SLG xSLG Diff. wOBA xwOBA Diff.
Pitch Pitch% BA xBA Diff. SLG xSLG Diff. wOBA xwOBA Diff.
Fastball 49.4 .266 .233 .033 .459 .461 -.002 .339 .327 .012
Curveball 21.7 .223 .191 .032 .291 .268 .023 .236 .218 .018
Slider 17.3 .233 .192 .041 .398 .326 .072 .306 .263 .043
Sinker 9.4 .400 .338 .062 .582 .580 .002 .459 .433 .026
Changeup 2.2 .267 .391 -.124 .733 .896 -.163 .413 .537 -.124

Well, you can see why he doesn’t throw his changeup much. But beyond that, by these measures, Pivetta’s getting jobbed a bit. His opponents’ average on balls in play is a crazy-high .342, which leads all qualified pitchers by almost 10 points and is around 90 points higher than Nola’s.

All Told...

This is one of the stranger seasons we’ve seen in a little while. Pivetta’s combination of strikeouts, limited walks, and good batted ball profile should have him enjoying a better season than his 7-11 record and 4.66 ERA would suggest. The improvements over 2017 are plain as day.

Perhaps he’s been victimized by this team’s poor defense more than others on the staff. The elevated BABIPs despite modest contact would certainly be a point in that argument’s favor, as would the thought that Pivetta isn’t really getting the “luck” element of BABIP to go his way, either. Vicious combo, if true.

What I see is a guy who really is having a breakout season - or, at least, has made big strides toward improving - whose stats don’t tell the truth about just how good he’s been. Perhaps, with an improved defense and fewer crushed mistakes next season, Pivetta will see fewer hits and runs on his ledger. It’s no guarantee, because this is baseball, but there’s a whole lot at work behind the scenes that makes Pivetta look like a solid option for next season’s rotation.