Jeffrey Springs Was in the Zone, But now He’s Down for the Count

The Rays continue to play phenomenal baseball. While their 14-game home winning streak came to an end on Tuesday night, they have won six of their last seven and boast what is easily the best run differential in the sport. Their average margin of victory is 3.7 runs, which is more than the Tigers, Marlins, and Royals are scoring per game. As if all that weren’t enough, Tampa Bay is only getting stronger. Zach Eflin returned from a back injury on Sunday and twirled five innings of one-run ball. Tyler Glasnow threw his first simulated game on Monday, a critical step in his rehab process as he works to rejoin the rotation. Meanwhile, top prospect Taj Bradley is waiting in the wings after making a fantastic big league debut.

For all that good stuff, however, the Rays have also been dealt a significant blow. On April 13 against the Red Sox, Jeffrey Springs looked down at his elbow after throwing a pitch; it would turn out to be his last of the 2023 campaign. Coincidentally, the Rays would lose their first game of the year the following day. Springs landed on the injured list with a diagnosis of ulnar neuritis but was later revealed to have torn his UCL; he underwent Tommy John surgery earlier this week to repair the ligament, leaving the Rays to go the rest of the way without the player who could have been their biggest success story. That’s a bold claim to make about a man on the same team as Yandy Díaz and Randy Arozarena, but that’s just how well Springs was pitching.

The left-hander broke out last season at age 29, earning 3.0 WAR in 135.1 innings, but this year, there was a spring forward (sorry) in his step. He was electric in two-plus outings, giving up only four hits and one run in 16 innings of work and striking out 24 of the 55 batters he faced. On the day he hit the IL, he ranked second among qualified pitchers in FIP, xFIP, and SIERA, trailing only Jacob deGrom in all three categories.

Underneath those excellent results was evidence of a new and improved approach. Springs was throwing more strikes and working with a refined arsenal against both right- and left-handed batters. Three starts is a tiny sample — just 211 pitches total — but the pitch-level data is promising enough to inspire dreams about what he could have done over a full season and provide far more information than the 55 batters he faced or the 16 innings he pitched:

Most notably, Springs threw far more pitches in the zone this season. His zone rate in 2022 was right in line with league average; this year, it ranked sixth among starting pitchers (min. 15 IP). Per the numbers on Baseball Savant, the difference is even more extreme: his zone rate jumped from 48.4% to 58.8%. From this data, it’s also clear that his zone rate on pitch number one was the driving force behind the change:

Throwing too many strikes in any given count can be dangerous — if hitters know to expect a pitch in the zone, they’re more likely to swing — but Springs was making it work. Of the 17 batters who swung on the first pitch he threw, just six put the ball in play, and only one earned a hit. He also earned an 0–1 count against 65% of the hitters he faced; the league average is 50%. His new approach was having the intended effect.

As you might guess, an 0–1 count is highly advantageous for a pitcher. The league-average FIP through 0–1 counts last season was 2.57; on 1–0, that figure rose to an ugly 5.62. Springs has had more success than the average pitcher, but still, he isn’t immune to the dangers of a 1–0 count. Throughout his career, he has always done well when he gets that coveted first-pitch strike:

On top of throwing more strikes, Springs was also throwing better strikes. In other words, he wasn’t just aiming for the zone and hoping for the best; he was making smarter choices and demonstrating pinpoint command. Consider, for instance, his work in the shadow zone. Last season, he had lots of success in the shadows. As Chris Gilligan explained in writing about Springs’ contract extension, “Springs found particular success around the shadow of the plate, where he was able to locate 45.3% of his pitches and induce swings 57.9% of the time, limiting hitters to a .240 wOBA.” The lefty continued using the shadow zone to his advantage in 2023, throwing 46% of his pitches in this area and inducing a .145 wOBA on such offerings. More of his shadow zone pitches, though, were within the bounds of the strike zone this season; when he didn’t induce a swing, he was more likely to earn a strike all the same. It’s a matter of inches, but it makes a difference.

Meanwhile, Springs was equally effective when he wasn’t throwing strikes. He didn’t use the chase zone as often in 2023, but he used it more efficiently, continuing to go there with his offspeed and breaking pitches and still seeking to induce swings and misses when he was ahead in the count. But he avoided the chase zone with his fastball and didn’t try to generate as much chase when he wasn’t ahead of the batter. As a result, he was still earning plenty of swings and misses in the chase zone despite throwing fewer overall pitches in the area:

And that’s not all! In addition to throwing with better control and command, Springs was throwing better pitches. Against right-handed batters, he used his usual fastball/changeup combo, but his changeup was nastier than usual. Against lefties, he introduced a brand new sweeper, bumping his slider to a tertiary role.

Let’s take a look at that changeup first. Springs already had a phenomenal cambio: According to the run value metric at Baseball Savant, it was the fifth-most valuable changeup in baseball last season. Most guys with a pitch like that would be perfectly happy to leave it as is, but Springs had a different idea. This year, he threw his changeup nearly a full mile per hour slower than he had as a starter the year before:

While his minimum changeup velocity remained constant, the number of pitches he threw around that minimum speed increased. In 2022, only 3.1% of his changeups were slower than 79 mph. This season, 8.3% of his changes were below that mark on the radar gun. On the other side of the coin, 14.9% of his changeups last year were as fast as his maximum velocity changeup in 2023.

To make things even better, Springs was throwing his four-seamer a little faster this season, up from 91.4 mph to 91.7. In 2022, 62.8% of the changeups he threw were at least 10 mph slower than his average fastball. This year, a whopping 93% of his changeups were at least 10 mph slower than his fourseam. Changeups thrive on velocity differential, so it’s no surprise his changeup was better than ever:

By improving his changeup, Springs also gave himself more flexibility with his fastball. Take a look at his fastball/changeup heat maps against right-handers from last year and from this year:

His changeup location (right side) was relatively similar in both seasons, but his fastball location looks quite different. He used his four-seamer all over the strike zone this year instead of keeping it in the upper outside corner. I can’t read Springs’ mind, but I wonder if his increased velocity differential played a role in all this. Perhaps he felt more comfortable using his four-seamer down in the zone because he wasn’t so worried about throwing his fastball and changeup in completely different locations.

What about that brand new pitch? The sweeper was Springs’ newest weapon against left-handed hitters. In 2022, the southpaw had reverse platoon splits; he was dominant against right-handed batters (2.66 FIP, 10.21 K/9) thanks largely to his stellar changeup, but against lefties, his numbers were much more pedestrian (4.29 FIP, 7.47 K/9). The biggest problem was his strikeout rate; Springs just couldn’t put lefties away. This wasn’t a new problem for him either. From 2019 to ’21, when he worked exclusively as a reliever, he always had better strikeout stuff against right-handed opponents:

Springs needed a weapon like his changeup to deploy against same-handed hitters. Last year, he relied on a fastball/slider combination. This approach worked fine, and indeed, his slider was more effective than it had been the year before. Even so, it wasn’t a nasty pitch. Springs managed only a 21.7% whiff rate and a .301 xwOBA with his slider against lefties. In 2023, he introduced his sweeper, and it became the weapon he was missing. He threw the pitch 26 times, posting a 55.6% whiff rate and a .104 xwOBA. He used it much like his changeup, pairing it with his fastball and throwing it at a low speed on the bottom outside corner. It moved less than the average sweeper, but its movement profile was actually rather similar to that of his change. I don’t want to draw any big conclusions about this sweeper quite yet, but the fact that it resembled a mirror-image version of his changeup is promising:

When a pitcher throws better pitches with better command, the results are usually impressive. That’s precisely what happened with Springs, although we won’t get any more results for the foreseeable future. Still, what he showed in his limited time was mesmerizing. It was enough to reveal why the Rays were so eager to extend him after just 25 starts.

Sadly, what happened next was enough to explain why Springs was so happy to accept the deal. He was in the zone one moment and down for the count the next. It’s an unfortunate reality that’s all too common in the sport we love. All we can hope is that Springs is back to pound the strike zone sometime in 2024.