Lance Lynn and Discovering Reduction within the Underlying Underlying Metrics

Lance Lynn was phenomenal in his remaining begin earlier than the All-Star break, going seven innings, putting out 11 batters, and permitting simply three baserunners. By recreation rating, his outing towards Toronto was among the many high 20 begins of the yr. But for those who want to concentrate on components solely inside a pitcher’s management — strikeouts, walks, and residential runs — it wasn’t even one of the best of Lynn’s season. By FIP, his most dominant efficiency was a 16-strikeout gem towards the Mariners a number of weeks prior. Over seven frames, he walked solely two and saved all the things within the ballpark. Even extra spectacular, all however one among his strikeouts got here on a swing and miss, as Lynn collected 33 whiffs on the night, probably the most by any pitcher in a single outing this season. His 16 strikeouts have been additionally probably the most in a single recreation this yr; no different pitcher has topped 13.

Lynn has two extra double-digit strikeout video games this yr, one every towards the Rays and the Twins. Only eight different pitchers have 4 or extra double-digit strikeout video games, and solely 4 have a number of begins of seven-plus innings, double-digit strikeouts, two or fewer walks, and nil house runs: Kevin Gausman, Zac Gallen, Logan Webb, and Pablo López. (The White Sox, being the 2023 White Sox, went on to lose all 4 contests, however that’s hardly a mirrored image of Lynn’s efforts on the mound.)

So why am I making an attempt to show that Lynn continues to be so good at what he does? Because the normal statistics haven’t been sort to him these days. No one has given up extra runs this season, and his 6.03 ERA is an unpleasant reminder that dangerous issues occur to good pitchers. His 4.81 FIP is decrease, however that isn’t saying a lot; his ERA ranks 63rd out of 64 certified starters, and his FIP ranks 54th. It’s simple to take a look at these numbers and assume Lynn’s age is beginning to present; he turned 36 in May, and his common fastball velocity has been dropping for the previous 4 years. He’s a chief candidate for age-related decline.

But for those who look previous ERA and previous FIP, the numbers paint an image of a pitcher who stays as regular and dependable as ever. The distinction between Lynn’s ERA and FIP is the second-largest amongst certified starters, behind solely Brady Singer. The distinction between his FIP and xFIP can also be the second-largest, simply trailing Yusei Kikuchi. Consequently, the gulf between his ERA and xFIP is wider than a Little League umpire’s strike zone:

This is certainly a great signal, and whereas Lynn absolutely isn’t happy along with his efficiency so far, no less than his xFIP is true in step with his profession common. Four years in the past, he had his greatest season by WAR (6.8) and earned down-ballot Cy Young votes for the primary time; his xFIP was 3.85. Two years later, he was a Cy Young finalist and got here 5 innings away from an ERA title; his xFIP was 3.82. This yr, his ERA is greater than Mariah Carey’s falsetto, and his Cy Young likelihood is slim to none. But his xFIP is 3.74.

Then once more, xFIP has its limits. When a pitcher has a FIP greater than his xFIP, it tells you one factor and one factor solely: His house run-to-fly ball ratio is above league common. HR/FB is extremely unstable in a small pattern dimension, and xFIP operates below the idea that with time, it normally regresses towards league common. To quote the FanGraphs glossary:

The variety of fly balls that go for house runs could be very delicate to pattern dimension that means that over the course of a season, the variety of house runs a pitcher permits could also be greater or decrease than their true expertise signifies. This is to not say pitchers aren’t liable for the house runs they did enable, however moderately to say that if you wish to choose how properly they pitched, xFIP will take away a few of these fluctuations in HR/FB% and offers you a greater thought.

I discover xFIP philosophically fascinating. For all intents and functions, it’s a model of FIP that makes use of fly balls as an enter as an alternative of house runs. Yet not like strikeouts, that are inherently good for a pitcher, and in contrast to walks, HBPs, and residential runs, that are inherently dangerous, fly balls are too complicated for such a inflexible dichotomy. Most of the time they’re good, however typically they’re very, very dangerous, and a few pitchers enable the dangerous sort greater than others. What xFIP presumes is that every one fly balls are created equal, and although this assumption is patently false, it’s a helpful metric nonetheless. Why? Because the purpose of xFIP isn’t to replicate every particular person pitcher’s true talents, however to eradicate excessive outliers. It’s prepared to be a bit of bit flawed about a number of pitchers to keep away from being completely flawed about anybody. It works as a result of the variance within the true expertise of MLB pitchers is a lot smaller than the potential variance in HR/FB over a small pattern of innings.

To deliver this dialog again to Lynn: the gulf between his FIP and xFIP introduces a dilemma. His 20% HR/FB is unsustainable, and nobody would dispute that. The distinction between his FIP and xFIP rightfully flags his HR/FB as an enormous outlier, so he’s due for some severe regression. The large query, nonetheless, is simply how a lot regression to anticipate. It’s arduous to look at a man surrender 22 house runs in 18 begins and never start to surprise if one thing is amiss, nevertheless it’s simply as arduous to look at Lynn’s dominant begins and assume something is flawed in any respect. Has he change into extra vulnerable to house runs, or has he merely been the sufferer of outstanding misfortune?

One technique to reply this query is to extend the pattern dimension, which is able to assist decide if Lynn’s HR/FB is something greater than a half-season fluke. As it seems, it was beneath league common in eight of his first 9 seasons. In 2022, it immediately shot up, and this yr it’s solely gotten greater:

Over his final 64 begins relationship again to May 2021, Lynn has given up about 400 fly balls. That’s the estimated quantity crucial for HR/FB to stabilize. He has a 14.4% HR/FB in that point, which isn’t practically as dramatic as a 20% fee, nevertheless it’s nonetheless considerably greater than common. In distinction, his HR/FB was considerably decrease than common over his earlier pattern of 400 fly balls. With that in thoughts, it begins to appear to be we’re coping with a worrisome development as an alternative of a mere fluke. To make issues worse, his HR/FB has been steadily rising since 2021:

But not so quick. The troubling development all however disappears once you cut up his numbers between house and the highway. Lynn spent his first six seasons on the pitcher-friendly Busch Stadium. In that point, his 6.5% HR/FB at house was elite, even for Busch Stadium requirements, however his 11.7% HR/FB on the highway was proper round league common. Since he got here to the American League in 2018, his HR/FB ratio has been a wholesome 12.5%. When he joined the White Sox in 2021 and began taking part in at Guaranteed Rake Rate Field, a veritable house run haven, his HR/FB at house skyrocketed, nevertheless it was nonetheless par for the course on the highway.

In different phrases, Lynn was higher than common at stopping house runs in St. Louis, and he’s been worse than common on the South Side of Chicago. On the highway, nonetheless, his HR/FB has all the time hovered round league common — till this yr, anyway. That being the case, I’m not satisfied Lynn has been trending within the flawed path for his final 400 fly balls. His house run drawback this season is new this season, so it’s the numbers from this season that demand our consideration.

Take a peek on the variety of hard-hit fly balls Lynn is giving up this season. This is the sort of contact that accounts for the overwhelming majority (about 96%) of house runs. Therefore, if a pitcher is giving up too many homers, there’s a great probability he’s giving up too many hard-hit fly balls. But Lynn? Not a lot:

How about pulled hard-hit fly balls? Pulled flies account for 61% of house runs, so if a pitcher immediately begins permitting extra pull contact, it may clarify a rise in his HR/FB. As destiny would have it, Lynn is, in truth, giving up extra pulled hard-hit fly balls this yr, however the distinction is slight:

Clearly, an abundance of pulled hard-hit fly balls isn’t the issue. Instead, the issue is that Lynn can’t catch a break. Of the 16 such balls he’s given up, 15 have left the park. That’s a 93.8% house run fee, in comparison with the league common of 60%. It’s an analogous story on hard-hit fly balls up the center; he’s permitting house runs at twice the common fee. Given the league-average HR/FB on hard-hit balls pulled or up the center, Lynn would have allowed 9 fewer homers this yr, bringing his FIP down from 4.81 to three.68. That’s an enormous distinction.

Another attention-grabbing wrinkle to the story is that Lynn’s house run drawback has solely been a difficulty towards left-handed batters and, extra particularly, solely towards his fastballs. Against righties, he has a wonderfully regular HR/FB ratio and a very good 3.26 xFIP. Versus left-handers, nonetheless, he has the very best HR/FB within the league, and 15 of the 16 house runs he’s allowed have come on fastballs. The numbers are excessive towards each his four-seamer and his cutter, nevertheless it’s the previous taking the brunt of the impression:

Even stranger nonetheless, Lynn’s four-seam fastball has been downright nasty towards right-handed hitters. Righties have a .196 wOBA, a .216 xwOBA, and a 40.4% whiff fee towards it; it’s been his greatest put-away pitch towards same-handed hitters, and he’s putting them out at his highest fee in years. There aren’t any important variations in his fastball’s motion profile or his launch level, and his velocity is barely down by half a mile per hour. Neither Stuff+ nor PitchingBot thinks his fastball is any worse this yr than final. Thus, whereas the hyper-specificity of Lynn’s house run troubles may level to a really peculiar drawback, it may additionally point out that is one large fluke. After all, if one thing actually wasn’t proper, wouldn’t you anticipate a pair extra signs to indicate up?

When a pitcher can’t cease bleeding runs, it’s pure to presume he’s doing one thing flawed. Yet for Lynn, his 3.74 xFIP is a brilliant mild on the finish of the tunnel. As terrible as all the house runs look, there’s no deeper indication that something is significantly flawed. Lynn’s FIP is dreary, and his ERA is grim, however fortunately, there’s aid within the underlying metric’s underlying metric. He ought to be simply high quality.