Derek Jeter on Thursday delighted those New York Yankees fans lucky enough — or well-heeled enough — to go to his final home game. First he smashed a near home run (it ended up being a double) in the opening frame. Then he finished his Yankee Stadium career in storybook fashion with a walk-off base hit in the bottom of the ninth:In the minds of most Yankees fans, it was classic Jeter — The Captain stepping up in the clutch, like he’s been doing for years.Then again, Jeter has also had the misfortune of playing his entire career during the sabermetric boom, which for the longest time denied the very existence of a true clutch hitter. Contrary to pinstriped dogma, Jeter couldn’t be something that didn’t exist.Sabermetricians have since softened on that stance, and further research has shown there are players with a demonstrable ability to improve their hitting when it matters most. (Of course, most of those players are guys you’d never expect, provided you’re not a huge Scott Spiezio fan.) Sabermetricians have also devised ever more inventive ways to measure what it means to hit in the clutch, chief among them being Win Probability Added (WPA) and its derivatives.WPA measures the change in win probability resulting from each plate appearance, putting a number on how much every play moved the needle toward a win in either team’s direction. Naturally, clutch situations will carry more WPA weight, because those moments produce the largest swings in win probability; there’s even a metric called Leverage Index that tracks how crucial a given situation is relative to the average plate appearance in Major League Baseball.(To give an example of WPA in action, Jeter’s final plate appearance at Yankee Stadium began with a 69 percent chance of New York winning. When the plate appearance ended, the Yankees had a 100 percent chance of a win — having, you know, won the ballgame. Therefore, Jeter earned 0.31 units of WPA with that single, making it the most impactful hit of the game for the Yankees.)If you add up all of those incremental pieces of win probability throughout the season, you’ll arrive at the total estimated number of wins a player added at the plate, giving a great deal of weight to when the player’s numbers were produced.That’s WPA.But there’s also a way to measure what a player’s WPA would be if we didn’t weigh clutch moments so much heavier than ordinary ones. To do that, sabermetricians have developed WPA/LI, which divides a batter’s WPA by the average Leverage Index of all his plate appearances, effectively producing a context-neutral version of WPA.Because any discrepancies between the two metrics are necessarily driven by contradictions in performance between big and routine moments, the difference between WPA and WPA/LI has been used to quantify clutch performance. And Jeter — despite his reputation, despite hits like Thursday night’s game-winner — hasn’t hit appreciably better or worse in pressure situations than in typical ones.As is the case with a few notable advanced metrics, the “Clutch” figures at Baseball-Reference and FanGraphs don’t match up exactly (here, probably because of slight differences in the sites’ win probability models). But both data sets tell similar stories. According to Baseball-Reference.com, there have been 1,077 players to have 1000-plus career games since 1940, and Jeter ranks 634th in Clutch — right ahead of Nate McLouth, Nick Swisher and Shane Victorino. FanGraphs’ Clutch data only goes back to 1974, but among the 1,663 qualifiers with 1,000 or more plate appearances since then, Jeter ranks 639th, slightly outpaced by Deion Sanders. Relative to the universe of MLB players past and present, Jeter’s Clutch differentials are only remarkable for how unremarkable they are.Maybe that’s the point. This particular statistical conception of clutch focuses narrowly on just one definition of the term — how much a player’s numbers improved or declined in big moments — but ignores the baseline level of performance from which each player was starting. Sanders was a relatively mediocre hitter who was relatively mediocre in the clutch as well. By contrast, Jeter was a fantastic hitter (and not just “for a shortstop”) for most of his career, regardless of the circumstance, so it means something that he performed to his usual high standards in clutch situations as well. That’s how you end up producing as many career WPA as a Hall of Famer like Ernie Banks, for instance.If anything is puzzling about Jeter’s relatively average crunch-time metrics, it’s not the contrast against his game-raising reputation as Captain Clutch — a good amount of which was myth-making hooey anyway. It’s that his style of play has traditionally been quite conducive to outperforming one’s baseline statistics during high-leverage at bats. Running a regression between FanGraphs’ version of Clutch and its various component stats, including walk rate, strikeout rate, isolated power and speed score, the two metrics most strongly associated with a player’s Clutch number are a lack of strikeouts and a lack of power. Jeter’s career K-rate was 2.9 percentage points below the MLB average, and his career isolated power was 25 points below the norm, so you’d think he’d have a leg up in the clutch. Not so, say the statistics.But his curtain call at Yankee Stadium demonstrated those traits perfectly. On Wednesday, my colleague Jonah Keri wrote extensively about Jeter’s signature inside-out swing, and his propensity for going to the opposite field. About how Jeter perfected the art of going the other way through hours of practice, gaining the consistency required to shoot the ball precisely into the gap between the first and second basemen. It was fitting, then, that his walk-off single showcased all of that. Jeter the “technician” produced hits like Thursday night’s farewell stroke in clutch and non-clutch moments alike.
It’s Black Monday — the day after the NFL’s regular season concludes — when 20 to 25 percent of teams (usually of the non-playoff-bound variety) have historically begun their offseason by firing (or otherwise parting ways with) their head coaches. This year, the New York Jets have fired Rex Ryan, Mike Smith is out in Atlanta and Jim Harbaugh left the San Francisco 49ers in a mutual split. Further changes may be coming.Teams don’t take these coaching changes lightly, but for all the focus on the coaching carousel, it’s been difficult for researchers to figure out how much who’s wearing the headset matters.Teams that change coaches have a strong tendency to improve the following season, which could be taken as prima facie evidence that swapping in a new coach makes a profound difference. But it also could simply be the residue of regression to the mean. A poor record is generally required for a team to consider dismissing its coach, but much of the differences in NFL team records is due to luck and not the comparative skill levels of the teams themselves. When that luck evens out, the team appears to improve, even if its underlying skill didn’t change all that much.And this phenomena is essentially what the research on NFL coaching changes has found. Although the average team to change coaches since 1994 has seen its winning percentage improve from .383 to .428 the next season, that’s mostly regression to the mean at work. In fact, once we account for the teams’ previous Elo ratings and the inexorable pull that a .500 record exerts on NFL teams from year to year, there’s little evidence that changing coaches helps teams at all.The aforementioned sample of teams had an average Elo rating of 1437 at the end of the regular season with their old coach, which tends to translate to a .463 winning percentage the following year whether a team changes coaches or not. But the season after making the change, those teams averaged a .428 winning percentage — about 35 points lower than we’d have expected based on their previous Elo ratings. This may speak to broader institutional issues that are correlated with coaching changes but beyond the influence of the coach himself, such as dysfunctional ownership, a poor general manager or players who consistently win less than point-differential-based metrics would predict.These types of findings lend credence to the theory that NFL coaching changes offer franchises little more than the illusion of control over their future. While it may feel satisfying to fans and owners to fire a coach after a disappointing season, it’s tough to quantify the real benefits of such a move — if any even exist.