The Brewers Might Have an Actual Ace

There’s not a soul out there that thought the 2017 Brewers would be as good as the 2017 Cubs. There’s not a soul out there that thinks the 2017 Brewers will be as good as the 2017 Cubs. And yet, the 2017 Brewers have been as good as the 2017 Cubs, at least by wins and losses, which are ultimately the only numbers that matter. The Cubs have three more wins than defeats. The Brewers can say the same of themselves. The Cubs have been billed as an active dynasty. The Brewers have been rebuilding. I’ll be damned. We’ll all be damned.

One key to understanding what’s going on: Before the start of the season, we ran our annual positional power rankings, and the Brewers rotation slotted in at 25th place. By actual WAR to this point, that same Brewers rotation ranks in seventh place. A certain amount of credit ought to go to Chase Anderson, who’s exceeding expectations. But he’s not exceeding them quite as much as Jimmy Nelson. In Nelson, it looks like the Brewers might have an ace.

I don’t throw that word around lightly. And Nelson has certainly teased before, without ever putting it all together. Yet, at present, there are so, so many positive signs, kind of similar to how James Paxton managed to emerge. Why don’t we start with the numbers that raised my eyebrows in the first place? You know strikeout rate, and you know walk rate. Here are the pitchers who have improved the most this season in terms of a blend of them:

Top Changes in K-BB%
Pitcher 2016 K-BB% 2017 K-BB% Change
Jeff Samardzija 14% 26% 12%
Jimmy Nelson 7% 18% 12%
Zack Greinke 14% 25% 11%
Chris Sale 21% 31% 11%
Luis Severino 12% 22% 10%
Trevor Bauer 12% 21% 9%
Jesse Hahn 2% 10% 8%
Nathan Karns 13% 21% 8%
Marco Estrada 14% 22% 8%
Clayton Richard 4% 11% 7%
Starting pitchers, minimum 40 innings each year.

By strikeouts and walks, Nelson right now looks basically the same as Dallas Keuchel and Johnny Cueto. A year ago, he was in the company of Doug Fister and Jered Weaver. Statistically, Nelson has taken this leap forward, and what’s even more interesting is how it’s been basically centered around improving against left-handed hitters. A similar table, but for pitchers against lefties, just:

Top Changes in K-BB% vs. Lefties
Pitcher 2016 K-BB% 2017 K-BB% Change
Jimmy Nelson 3% 24% 21%
Jeff Samardzija 12% 26% 13%
Marco Estrada 13% 24% 11%
Zach Eflin 0% 10% 10%
Dan Straily 6% 15% 9%
Michael Fulmer 10% 18% 8%
Zack Greinke 16% 23% 8%
Joe Musgrove 9% 15% 5%
Jake Arrieta 11% 16% 5%
Luis Severino 14% 18% 4%
Starting pitchers, minimum 100 lefties faced each year.

Since Nelson reached the majors, lefties have hit him to the tune of a .340 wOBA, striking out less than a fifth of the time. But for this season alone, that wOBA has dropped to a woeful .259, with strikeouts nearly a third of the time. Nelson’s a righty, yet all of a sudden, he’s changed into a guy who might have a reverse platoon split. No one ever would’ve expected that, and we can at least offer one simple explanation for Nelson’s overall improvement: strikes. He’s just throwing a whole bunch of strikes.

Out of 125 pitchers a year ago that Baseball Reference considered qualified, Nelson ranked 98th in strike rate. Out of 129 pitchers this year that Baseball Reference considers qualified, Nelson ranks third in strike rate. That, obviously, is a massive jump, and although Nelson has managed to get some more swings out of the zone, that’s not so much the secret. Nelson’s just staying in and around the zone more than he ever has:

Nelson right now has baseball’s highest zone rate. His zone rates have never been bad, but now he’s pitching aggressively, pitching with confidence. And, given his numbers, why wouldn’t he? Nelson’s showing the best command and control of his life, and since he gets his heater into the mid-90s, he’s certainly not hurting for stuff. He’s locating it, and it turns out locating better makes talented pitchers better. Who knew?

One is always programmed to wonder what’s different, underneath it all. One change is that, compared to prior seasons, 2017 Nelson is throwing more four-seam fastballs, instead of two-seamers. This is true in particular against lefties, and four-seamers tend to run smaller platoon splits. That’s far from the whole explanation. Borrowing from Brooks Baseball, we can see that Nelson has also been adjusting his arm slot:

That represents a drop of a few inches from Nelson’s peak. There’s a change to the pitch mix, and there’s a change to the arm slot. There are also changes elsewhere in the delivery. Here’s a representative pitch from the middle of last season:

Here’s a pitch from Nelson’s last time out:

In there, a couple things are visible. For one thing, recent Nelson has simplified, throwing from essentially the stretch all of the time. That’s supposed to eliminate unnecessary movement, and Nelson is far from the first pitcher to attempt such a tweak. This is an adjustment Nelson actually kicked off down the stretch last summer. And then for another thing — I feel like I’ve written pretty often lately about pitcher feet. Check out Nelson’s front foot:

That’s 2016 on the left, and 2017 on the right. It’s just one more minor change, but 2017 Nelson isn’t throwing so much across his body, because he’s stepping more directly toward the target. Look at the visible area between his feet, even just in two dimensions. There was a gap, and now there’s hardly anything. Some pitchers are more comfortable throwing across their bodies, and there’s no such thing as a universally applicable mechanical improvement, but what we have here is a pitcher who has clearly improved. All of these tweaks together have turned Nelson into something he’s never before been.

You never know how much of a player’s gains he’ll be able to hang onto, as the league starts to come around, but I’m greatly encouraged by Nelson’s newfound ability to throw strike after strike. And while I realize that Nelson wasn’t very good in last year’s second half, as he began to adjust, sometimes adjustments take time to feel normal. Sometimes little adjustments continue until something or everything clicks. Nelson throws hard and he’s getting ahead, and with lefties in particular, he’s turned a weakness into a strength. James Paxton altered his delivery and figured it out in his age-27 season. It seems like Jimmy Nelson has altered his delivery and figured it out in his age-28 season. The Brewers, probably, won’t be sitting in first place in their division much longer. Yet this year was and has always been about player development. There’s a convincing argument to be made that Jimmy Nelson has developed.

Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

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One big thing that seems to be missing before he earns the “ace” label (besides sustaining this performance over a longer period) is the ability to go late in games. The only pitcher in his vicinity on the WAR leaderboard who averages less than his ~5.85 IP/Start is McCullers, and obviously Milwaukee doesn’t have anything remotely resembling Houston’s bullpen situation.


7 and 8 innings in his last two starts offers some hope.