I was very surprised to find that basically nobody is talking about the season that Milwaukee Brewers’ starter Jimmy Nelson is having this year. I’m not really surprised that it’s a career year for Nelson, as the chart below shows, but that he ranks among the best pitchers this season, not just in the National League but throughout the majors. He’s posted numbers that you’d expect from an ace-level pitcher, even though the last two years have suggested he was a middle-of-the-rotation type.
Nelson is primarily a four pitch pitcher, using a combination of his four-seam fastball, two-seam fastball, knuckle-curve and slider, although he just began throwing the curve in 2015. He does mix in a changeup every now and again to left handed hitters — about 5 percent of the time — which gives him a fifth pitch.
With the exception of Nelson’s first 10 innings in 2013, he is currently at career highs in velocity on all five of his pitches. The average on his four-seamer is now only slightly under 95mph, and his average curveball is even closer to 85mph. In that respect he’s very much similar to Houston Astros’ starter Lance McCullers, who also features both a hard fastball and a hard knuckle-curve.
In fact, the similarities go much deeper than that. Among all pitchers with at least 80 innings this season, Nelson is second only to Lance McCullers in total pitch value on the curveball. Granted Lance McCullers’s curveball is over four points higher than Nelson’s — so it’s basically in a league of it’s own — but they’re still the top two in the league.
Another similarity between the two is the fact that their two-seamer is their best fastball, as Nelson’s two-seamer is ranked fifth in the majors in pitch value while McCullers’s is ranked 11th. By contrast, both of their four-seam fastballs were negative in terms of pitch value.
Nelson’s four-seamer is an interesting story, as so far this season he’s tallied the most strikeouts with it (good), but he’s also allowed the most extra-base hits off it (bad). That’s not the most surprising part either; he’s allowed 34 hits off the four-seamer while allowing 52 off of his two-seamer, yet the two-seamer has given up half as many extra-base hits. The contact batters are making with his four-seamer is evidently much more authoritative.
His curveball has really evolved this year as he’s already set a career high in strikeouts with it in a season. The chart below shows how much better the pitch has gotten since he started throwing it in 2015.
At this point his slider is simply not getting the swings and misses late in the count that he typically had in the past. He continues to use it late in the count, although not as often, but it’s not resulting in whiffs he was accustomed to in the first few seasons. Hitters may have adjusted to this pitch because it was his primary out pitch over the previous four seasons, with 141 of his 353 strikeouts between 2013 and 2016 coming on the slider. The chart below shows the change in swinging strike rate on the slider over his career.
Despite the slider not getting the swings and misses Nelson enjoyed earlier in his career, he’s still 16th in out-of-zone swing rate and 13th in overall swing rate among 72 qualifiers. Complimenting these high swing rates are low contact rates, as his out-of-zone contact rate is the 23rd lowest, and his total contact rate is 21st lowest. Lots of swings and not much contact yields a high swinging strike rate (a category in which Nelson is currently ranked 19th). He does all this while also pounding the zone, with the 12th-highest zone rate rounding out a top-25 rank in all plate discipline categories.
Even with a slugging percentages well over .400 off of his slider and four-seamer — which combine for a total of over 45 percent of his total pitch usage — Nelson is still 19th in soft contact rate and 20th in opposing slugging percentage. As pitchers adjust to the pitches that he leaned on most in the past, Nelson has been able to use his other pitches, mostly the curveball, to find reliable success.
Overall, he’s currently 20th in ERA with a very respectable 3.43 through just over 120 innings of work. He’s also 9th in FIP with a 3.22 and 9th in fWAR with 3.1, already a career high by over a whole run. He’s currently 9th in SIERA, which is a metric he never came close to leading before. He previously finished 6th-worst in 2016 and 27th-worst in 2015 out of over 70 pitchers.
This season is a far cry from last season, in which Nelson lead the league in walks with 86 in 179 and 1/3 innings, good for a walk rate of well over 10 percent. This year he’s almost cut that in half, down to exactly six percent, which puts him at 13th in the majors.
Not only has he cut his walk rate down, he’s also really ramped up the strikeouts, with a career high strikeout rate of almost 27 percent (good for 13th in the league). Nelson has four double-digit strikeout games so far this season, which is something he had only accomplished once before in his career; in a start against the Cubs on May 8th 2015, Nelson fanned 11 over seven innings. This season he’s struck out 11 twice, once against the Lost Angeles Dodgers — as shown in the video below — who are one of the better teams in baseball.
Combine the decreased walk rate with the increased strikeout rate and the result is the 11th-best strikeout-to-walk ratio among starters.
As good of a season as Jimmy Nelson is having, his .330 batting average on balls in play is currently the 11th highest among qualified starters. This suggests he’s getting poor support defensively or that he’s been unlucky with pitch outcomes. His ninth-lowest xFIP of 3.22, as well as his ninth lowest xFIP- among qualified starters, also support this theory that he’s still got room to improve. Part of that could come from where Nelson is pitching, however, as Brewers Park is a hitter-friendly ballpark, currently ranked 5th best for hitters in 2017 according to ESPN. The park adjusted metrics are helpful here; he’s currently seventh in FIP-, and as I mentioned a moment ago, ninth in xFIP-.
We’re through 20 starts this season, and judging from Nelson’s past two seasons he will likely make around 30 to 32 starts in total. Even with that many starts left, he’s only 16 strikeouts shy of his career high of 148. His current pace puts him somewhere close to 190 innings and 200 strikeouts by the end of the season, which could potentially put him in the Cy Young conversation if he continues getting the same results.
He obviously won’t win the award over guys like Max Scherzer or Clayton Kershaw, who are both having unbelievable seasons, but to finish in the top five or even the top 10 should be taken as a huge victory for Nelson.
He’s turned himself into a completely different pitcher this season, and is having a career year despite numbers that suggest luck and defense haven’t always been in his favor. He’s fixed several of the areas of weakness that caused him to struggle in the past while also finding new success with his knuckle-curve and two-seamer. With the Brewers in the hunt for an NL Central crown, Nelson will be instrumental in whether they succeed or fail both down the stretch and in the postseason. Regardless of whether Milwaukee acquires another starter at the deadline — as some have suggested they will — Nelson could be their ace this season that helps them make a run.
Ron Wolschleger is a pitchaholic and a Contributing Writer for Beyond the Box Score as well as Bless You Boys. You can follow him on Twitter at @FIPmyWHIP.