It’s not a news flash that Juan Soto was great in 2018. The simplest of statistics could tell that story. His OBP started with a 4. His slugging percentage started with a 5. He had 22 homers in a mere 116 games. However, the real hype starts when you dig into the numbers a little more. Juan Soto was 19, and he walked 16% of the time in the big leagues while putting up a 146 wRC+. People are making historical comparisons because that’s the only way to appreciate such a tremendous feat. No one in history has put up a better batting line before their 20th birthday, and the only people to come close are Mel Ott, Tony Conigliaro, and Ty Cobb. When you put it that way, maybe we’re underselling how great Soto’s 2018 was.

I’m not writing today to remind you of how good Soto’s 2018 was (like, really good though! Really good!). Instead, let’s talk about the approach he used to generate those numbers. Here’s a leaderboard of the 10 best hitters in baseball by wOBA last year, minimum of 450 PA. I’m using wOBA instead of wRC+ for compatibility with data further along in the article:

Well, that’s about what you’d expect. Ten great hitters, or potentially nine great hitters and Max Muncy, depending on how you feel about him. Paul Goldschmidt was eleventh if you want to leave Muncy out of this. That alone is already amazing. What makes it really impressive, however, is that Soto did it all against fastballs. I’m going to throw another leaderboard at you. Read the rest of this entry »

Photo: Keith Allison

Before the 2017 season, Aroldis Chapman signed a near-record-setting contract to play for the Yankees. The club knew what they were getting, both on and off the field — they had traded Chapman to the Cubs earlier that year, and now they were bringing him back. More broadly, baseball knew what the Yankees were getting — a dominant closer with a dominant fastball. Just how much of an outlier was Chapman’s fastball? Well, when MLB created a fastest pitches leaderboard to show off Statcast, they added a button called the “Chapman filter.” In 2016, Chapman threw the thirty fastest pitches in the majors. It’s not much fun looking at a leaderboard that’s just one guy’s name over and over again.

Fast forward a year, and all the signs were trending downward. Chapman put up a 3.22 ERA and a 2.56 FIP in 2017, both the highest marks since his rookie year. He struck out a career-low 32.9% of the batters he faced (which is still pretty good for a career-low). His average fastball velocity declined by a mile an hour. By early 2018, he’d even been dethroned atop the fastest pitch leaderboard by Jordan Hicks. The human brain is an amazing pattern-matching machine, and we’ve seen this one plenty of times. Closers often break — it’s one of the reasons Chapman’s five-year contract was considered a risk when he signed it. The king has his reign, and then he dies. It’s natural.

Well, a funny thing happened on the way to irrelevance. Aroldis Chapman reinvented himself in 2018, and while he didn’t quite get back to his game-breaking 2014 highs, he recorded a 2.45 ERA and an even more absurd 2.09 FIP. He struck out 43.9% of the batters he faced, the second-highest rate of his career. How did he do it? Did he reach back a little further and take the velocity lead back from Hicks? Not even close, as his average fastball velocity declined another tick in 2018, and he finished a distant third in that category, the first time he wasn’t the hardest thrower in baseball since 2011. Instead, he leaned on his slider — one that may be the best in the game today. Read the rest of this entry »