Allow me to present you with assorted statistics from two players. They aren’t exhaustive, of course, and I’m trying to mislead you, but still:
Two Mystery Lines
|Batter||Barrel%||Hard Hit%||xwOBACON||Max EV (mph)|
Batter A looks a little bit better. He hit the ball hard more frequently and topped out at a higher exit velocity. Player B had a better xwOBACON — a mouthful of letters that simply means using xwOBA to measure a player’s quality of contact — but I think I’d take the hard hit rate and maximum EV of Player A anyway.
Here’s a further wrinkle: both of these players are, by reputation at least, among the best defenders at their respective positions. Player A is the better defender relative to his peers — he’s won five Gold Gloves to Player B’s zero — but Player B plays a position 20 runs up the defensive spectrum, meaning he has provided more defensive value per plate appearance in his career than Player A. Who would you rather have had on your team in 2020?
From these statistics — and specifically these statistics — it’s not exactly obvious. You might have a leaning one way or the other, but it can’t be more than a 60/40 decision. That’s not to say that you would have a tough choice going forward — Player A just turned 28, while Player B will turn 38 before the start of the 2021 season. Also, you don’t actually get to pick which one to add to your team, because Player A is under contract for next year. You could totally add Player B, though: he’s a free agent after a two-year run with the fifth team of his major league career.
Enough with the blind nonsense: Player A is Mookie Betts. You should have taken him! Player B is Jeff Mathis, frequent butt of incompetent-hitting jokes and widely reputed to be one of the worst hitters of all time. Sounds like we’re going to need to do some further digging.
Mathis’ lack of hitting prowess is no joke. Take a look at his 2015-2019 seasons from the lens of the statistics we used above:
Jeff Mathis, Contact Quality, ’15-’19
|Season||Barrel%||Hard Hit%||xwOBACON||Max EV (mph)|
Yikes. This isn’t how it works, but just think about this: if you added his barrel rates from 2017-2019, it would be lower than his rate from 2020. He barreled the ball up six times in those three years over the course of 400 batted balls. In his 39 chances this year, he managed three barrels. Yes, this is a totally new hitter.
Of course, it’s not really a totally new hitter. His .161/.221/.355 line doesn’t require any advanced translation — it’s awful. Meanwhile, Betts hit .292/.366/.562 and finished second in MVP voting. What are these fancy Statcast metrics for, again?
Let’s not be too hasty — I cherry-picked those number to paint Mathis in the best possible light and Betts in the worst. Betts’ game isn’t barrels and dingers, though he does those things ably enough; he’s a contact machine with an otherworldly batting eye, with his power merely an extension of those core strengths. Here, let’s do this again:
Okay, yeah, give me Mookie here. Mathis is a bad hitter, and I’m not even remotely trying to argue that he isn’t. The old blind resume trick is a fun way to misdirect and highlight strong or weak points in different players’ games. Jeff Mathis isn’t Mookie Betts’ equal in any way.
True as that may be, Mathis really did do much better on contact in 2020. You wouldn’t notice it from the batting line, and the improvements that he made may be undone by the ravages of aging in the offseason. Heck, he might not even get a contract next year. Before he rides off into the sunset, though, I thought I’d take a moment to appreciate a bad hitter doing good things, even if he didn’t get rewarded for it.
What’s the best thing a hitter can do? Hit the ball hard and in the air. Mathis was surprisingly good at that in 2020. Among batters with at least 25 batted balls, he finished 15th in the rate at which he hit one hard (95 mph or more) and at a good angle (20 to 35 degrees). Sure, it’s only seven of 39 balls, but that wedged him between Teoscar Hernández and Max Muncy, great company to be in.
Three of those balls became his three home runs, which makes sense — it’s hard to hit a home run outside those angles unless you hit it really hard, and that’s not Mathis’ game. The other four all became outs, and c’mon, that isn’t fair to old Jeff. Watch him mash one to deep center, deep enough to allow a first-to-second advancement:
Here’s another shot to deep center, this time on more of a line:
I won’t make you watch two more videos of outs, but you get the idea. Mathis had five batted balls that qualify as “Solid Contact” in Baseball Savant’s contact quality classification. He went 0-5 on them, not exactly what you’d hope to see. In fact, his launch angle chart looks spectacular:
That peak at 20 degrees is awesome, because it almost doesn’t matter how hard you hit the ball at 20 degrees; it’s either a flare or a sharp line drive. In previous years, he was far less precise:
Is this some hidden case for Jeff Mathis, late-blooming hitting phenom? Absolutely not. For all those well-struck balls that found gloves, his xwOBA on contact was still only roughly league average. xwOBA is a descriptive statistic — in other words, it tells you how valuable that player’s contact was in a given year, independent of what actually happened after the ball was in play. It doesn’t tell you much about what you should expect from them in the future, and well — I can tell you what you should expect from Mathis in the future.
Rather, this is a nod of recognition to Mathis for doing what he could to get better. He’s never going to be a good hitter. He’s never going to be a decent hitter. In 2020, though, he did the things that good hitters do when he made contact with the ball. He elevated, hit it hard, and did all the things we look for in breakout hitters. He improved his wOBA by 55 points while moving from a hitter’s park to the Costco where fly balls go to die.
Sure, if he hit his Statcast-estimated expected numbers, he’d still only have hit .203/.262/.355, but that’s not the point. It’s neat to see hitters improve. Mathis had never previously posted even an acceptable set of batted-ball metrics. Last year, his wRC+ was TWO — literally two! — and the Rangers led the majors in pinch hitting value merely by hitting for him. This year, he improved to the point where I could fudge the data and make him look like Mookie Betts. If that’s not worth celebrating, I don’t know what is.