Lance Lynn first received a rotation spot in 2012 when St. Louis’s then-ace Chris Carpenter went down in Spring Training. Lynn inherited the rotation spot vacated by Carpenter, but did not inherit his role as staff ace, into which Adam Wainwright stepped after missing 2011 while recovering from Tommy John surgery. The Cardinals have once again lost their ace, with Adam Wainwright out for the season because of an Achilles injury. This time, Lance Lynn, secure in his spot in the rotation and current de facto ace, appears poised to drop the de facto qualifier and be one of the top ten pitchers in all of baseball.

As Jonah Keri wrote yesterday, not much was expected of Lynn when he was drafted, but over the last year he has been one of the better pitchers in the National League. The Cardinals tweaked Lynn’s delivery in the minors, instructing him to move his hips more to gain greater leverage towards the plate. The moves helped Lynn throw in the mid-90s out of the bullpen in 2011, and kept his fourseam fastball in the 92-93 mph range as a starter. Lynn has been solid and durable, but not spectacular, as a starter over the past three seasons slotting behind Adam Wainwright. In the early part of this season, he has taken a step forward, mirroring the career of Max Scherzer.

Cardinals fans are well acquainted with Scherzer, who is from St. Louis and attended the University of Missouri. Scherzer has always been good, but he was not great until his fourth full season as a starter. Scherzer and Lynn were both college pitchers drafted in the first round, with Scherzer going 11th in 2006 and Lynn going in the supplemental round at 39th in the 2008 amateur draft. Both players got their first extended exposure as starters when they were 24 years old, although Lynn’s birthday in May comes three months ahead of Scherzer on the calendar, making 2012 Lynn’s age-25 season and his first as starter while Scherzer’s 2009 season is his age-24 year. The two pitchers were remarkably similar in the their first three years of starting, and Lynn has matched Scherzer’s fourth season this year.

Scherzer IP Lynn IP Scherzer K% Lynn K% Scherzer BB% Lynn BB% Year 1 170.1 176.0 24 24 9 9 Year 2 195.2 201.2 23 23 9 9 Year 3 195.0 203.2 21 21 7 8 Year 4 187.2 41.1 29 29 8 8

Both players lost their spots in the rotation briefly early in their respective careers. Scherzer was sent down to the minors in 2010; Lynn, to the bullpen in 2012 ahead of the playoffs. In their first three seasons starting, Lynn’s 9.9 WAR slightly outpaced Scherzer’s 8.7 WAR, and both pitchers had similar trouble against left-handed hitters.

v. LHH (Year 1-3) BA OBP SLG wOBA Max Scherzer .259 .335 .434 .338 Lance Lynn .254 .357 .410 .340

The reason for the slightly different WAR numbers during those seasons could be due to the number of left-handed hitters each pitcher faced. Scherzer faced off against a lefty 54% of the time during those first three years while Lynn only went up against 46%, a situation that is not likely to change, as Jeff Sullivan noted in the offseason. There was some hope that Lynn had improved against left-handed hitters last season when his walks went down slightly and the slugging percentage against dropped significantly. Indeed, he has struck out more left-handed hitters this season, with seven of his nine strikeouts in his last start against Cleveland coming against lefties and 21% of lefties overall, but his walk rate and wOBA against are right in line with his career averages. Mostly, Lynn has made his improvements thus far by moving from merely excellent to absurdly dominant against right-handed hitters.

Lance Lynn’s 1.57 FIP against righties so far this season is more than half a point below second-place Rubby de la Rosa. Lynn’s 38% strikeout rate is behind only James Shields (just ahead of Max Scherzer), and his strikeout- and walk-rate differential of 34 points is the best in the majors. Lynn’s fastball has been very effective this year, and only Bartolo Colon and Jarred Cosart have thrown a higher percentage of fastballs this season. Including Lynn’s sinker and cutter in addition to his fourseam fastball, he throws a hard pitch roughly 90% of the time. Against righties, Lynn has located his fastballs better than he ever has in his career.

From 2012 to 2014, if damage was done against his fourseam fastball, the pitch was generally inside and low. Here is a chart showing Lynn’s slugging against his fourseam fastball to right-handed hitters during his first three years starting, from Brooks Baseball.

Note the red areas occupying basically the entire inner half of the chart and all the slugging figures in the .500 to .700 range.

Now here is Lynn’s whiff rate map on the fourseam fastball to right-handed hitters over the same time period, again from Brooks Baseball.

It is somewhat incredible that Lynn can throw a fastball right down the middle of the plate and get a swing and a miss 17% of the time. Low and inside on the fastball does not work well for Lynn against right-handed hitters, but if he goes up or away, he gets great results.

With that in mind, consider this next chart, also from Brooks Baseball. These Lynn’s fourseam fastballs to right-handed hitters so far this season.

What Lynn has done so far this season is to avoid the danger zone on the inside and low portions of the chart — and gotten good results in the process, like on this fastball to Jayson Werth.

Lynn appears to miss his target, but Werth cannot catch up to the fastball up in the zone. Hitters cannot crowd the plate only looking for outside pitches because Lynn uses his sinking fastball around 20% of the time, and against right-handers it goes almost exclusively to the inside part of the plate. Here it is against Ian Desmond.

Lynn is not without his concerns. As a workhorse, Lynn has gone roughly six innings per start throughout his career and done the same so far this season, but if he is to hit 220 or more innings — a figure the Cardinals need after losing Wainwright — he will need to consistently pitch seven innings per game. Unlike Scherzer, as well — who improved against left-handed hitters in his fourth season — Lynn has yet to do that consistently. Finally, one must acknowledge that Lynn has also gotten off to hot starts before. After seven starts last season, for example, his strikeout rate was 25.4%, but then only 19.7% for the rest of the season. The same was true in 2013: after seven starts, he’d produced a strikeout rate of 27.0%; after that, only 22.1%.

If Lynn backslides slightly on his strikeout rate again this year, he will retain his workhorse designation, which is an achievement unto itself, but right now he looks like an ace. The ZiPS updated projections have Lance Lynn slotted ahead of Chris Sale, Matt Harvey, Zack Greinke, Jon Lester, Gerrit Cole, and Johnny Cueto. In the National League, he’s behind only Max Scherzer, Clayton Kershaw, Madison Bumgarner, and Jordan Zimmerman. If he can keep mirroring Max Scherzer, Lynn’s designation of “de facto ace” will rightly have a few words edited from it.