In the winter of 2017, Lance Lynn was coming off a season with a solid 3.43 ERA but poor peripheral numbers and couldn’t get the multi-year deal he desired, eventually settling with the Minnesota Twins. Lynn got off to a rough start, but from May on he put up a 3.34 FIP and a 4.13 ERA with the Twins and Yankees (following a trade), with the former number making Lynn one of the top-15 pitchers in the game and the latter number befitting an average-to-slightly above-average innings-eater. Heading into 2018, Lynn was paid based on his poor FIP and not his solid ERA, but heading into 2019, Lynn received a contract based on his average ERA and not on his very good FIP. Lynn agreed to a three-year deal worth $30 million to pitch for Texas, and 15 starts into in his Rangers career, the MLB pitching WAR leaderboard looks like this:

MLB Pitching WAR Leaders Name IP K/9 BB/9 ERA FIP WAR Max Scherzer 106.1 12.4 1.9 2.62 2.19 4.2 Lance Lynn 93 9.9 2.3 4.16 3.00 3.2 Hyun-Jin Ryu 93 8.2 0.5 1.26 2.51 3.1 Matthew Boyd 88.2 11.4 1.7 3.35 3.00 2.8 Chris Sale 90.1 13.0 2.1 3.49 2.80 2.8 Lucas Giolito 85.1 11.0 3.1 2.74 3.08 2.8 Gerrit Cole 96.2 13.8 2.3 3.54 3.10 2.7 Jose Berrios 97.2 8.7 1.6 2.86 3.52 2.6 Frankie Montas 82 9.7 2.3 2.85 2.89 2.6 Charlie Morton 87.1 11.0 3.2 2.37 2.88 2.5 Jacob deGrom 91 11.1 2.0 3.26 3.21 2.5 Jake Odorizzi 76.1 10.0 2.8 2.24 2.99 2.4 Stephen Strasburg 96 10.8 2.3 3.75 3.27 2.4

There’s Max Scherzer at the top, and right behind him is Lynn with 3.2 wins above replacement on the season. While some might have the urge to point to Lynn’s 4.16 ERA and insist there is something wrong with WAR, particularly at FanGraphs, I would request fighting against any such urges. First, I’d like to note that over at Baseball-Reference, Lynn’s 2.7 WAR ranks 12th in all of baseball and isn’t too far off from the one above. As for that ERA, Lynn has put together an unusual season with respect to runs allowed. First, Lynn has no unearned runs on the year. While most pitchers’ earned run totals are around 90%-95% of their runs allowed, Lynn’s runs have all been earned. Indeed, Rangers pitchers outside of Lynn have earned run totals that are 93% of their total runs allowed. While it is possible that Lynn has benefited from great defense, that’s unlikely as we’ll get to below. In any event, that explains roughly 0.3 of Lynn’s higher ERA.

As for the main culprit for Lynn’s higher ERA, look no further than his .345 BABIP. For his career, Lynn has given up a .305 BABIP and his ERA and FIP are an identical 3.62. There’s little reason to think that the .345 BABIP is an accurate reflection of Lynn’s talents, but given that Lynn’s BABIP a year ago was .336, it is a topic worth exploring. Taking a quick look at Statcast tells us that Lynn’s expected BABIP this season is about 30 points higher than the results on the field. Perhaps not coincidentally, Rangers pitchers have a 34-point differential between their expected batting average on ground balls (.262) and their actual batting average on ground balls (.294). Whether it is poor shifting, poor defense, or simply bad luck, when Rangers pitchers have allowed ground balls, they have turned into outs at a much lower than expected rate.

Interestingly, Lynn is a ground-ball pitcher some of the time and but also a fly-ball pitcher depending on the situation. When the bases are empty, Lynn’s ground-ball rate is 37%. All eight of Lynn’s home runs allowed have been solo shots, and he has posted a 28% strikeout rate with the bases empty. With runners on, Lynn’s strikeout and walk rates go down slightly and his ground-ball rate goes up to 45%. While we could chalk it up to randomness, Lynn’s pitch usage is different with runners on base.

Lance Lynn Pitch Usage Percentages Runners on Bases Empty Difference Two-seam 25.9 15.5 10.4 Curve 10.6 10.1 0.5 Change 3 4.3 -1.3 Cutter 16 19.4 -3.4 Four-seam 44.5 50.7 -6.2 Through June 18, 2019

With runners on base, Lynn shifts his pitch mix slightly to try and induce ground balls. The strategy works and simultaneously doesn’t work. It works because he hasn’t allowed a home run with runners on, which has led to a very low 2.02 FIP so far this season, second-best in the game to Scherzer’s 1.97 mark. Lynn’s xwOBA of .263 with runners on would seem to indicate that some of the lack of homers is earned, or at least deserved. That he’s received an actual wOBA of .290 with runners on is an indicator of either bad luck or poor defense. I’m not definitive about either one, but it seems unlikely to be Lynn’s fault. There’s an argument to be made that Lynn’s aggressive approach with the bases empty (his expected BABIP is nearly identical to his BABIP in those situations) leads to more men on base, and that even neutral luck might allow those runners to score at a higher rate than his 2.99 FIP might indicate, but his approach with runners on should be leading to a lot more outs.

As for Lynn’s success generally, his pitch splits indicate almost no difference from his career numbers.

Lance Lynn Pitch Results Career wRC+ 2019 wRC+ Career SwStrk% 2019 SwStrk% Four-seam 98 106 10.7% 11.6% Two-seam 124 147 6.9% 6.0% Cutter 88 40 10.9% 11.7% Curve 78 92 12.3% 12.7% Through June 18, 2019

The cutter has gotten better results, and he’s throwing it harder on average this year than he has in the past, though Lynn is a pitcher who has varied his speed on his pitches so it is hard to glean too much from the harder average. What Lynn has done with the cutter is throw it a lot more often.

Lance Lynn Pitch Usage Season FA% FC% SI% CH% CU% 2011 59.9 % 1.8 % 13.4 % 2.7 % 22.2 % 2012 49.1 % 5.3 % 21.0 % 6.7 % 17.9 % 2013 52.7 % 12.8 % 20.5 % 3.9 % 10.1 % 2014 52.8 % 10.5 % 25.8 % 2.7 % 8.3 % 2015 56.5 % 8.0 % 27.5 % 3.1 % 4.8 % 2017 38.8 % 11.8 % 42.2 % 2.6 % 4.6 % 2018 44.8 % 11.3 % 32.7 % 2.1 % 9.1 % 2019 48.4 % 17.6 % 19.5 % 4.3 % 10.3 % Total 49.4 % 10.3 % 27.2 % 3.5 % 9.5 % Through June 18, 2019

Lynn has dropped his sinker usage considerably, back closer to 2013 and 2014 levels, which also happened to be Lynn’s best years with the Cardinals. He pitched injured for half of 2015, then missed 2016 recovering from Tommy John surgery before that 2017 season that produced poor peripherals but a solid ERA. What Lynn has done to make himself even better is use that cutter much more often. It’s been one of his better pitches in limited use throughout his career, and replacing a bunch of sinkers, which might prevent homers but don’t do much else, with cutters has helped lead to better results, including more strikeouts. It’s been a strange trip for Lynn since the end of that 2015 season when he pitched with pain ahead of surgery, but he’s finally back to the pitcher he was five years ago. With increased use of the cutter at the expense of the sinker, he’s the best he’s ever been. He’s probably going to allow a few more homers than he has at this point, and some of them are going to happen with runners on base, but Lynn has come up with a formula that has made him one of the best pitchers in baseball for nearly half a season.