Jeremy Jeffress Continues to Evolve
The veteran reliever has crafted several variations of himself to stay in the league, and he’s doing it once again with the Cubs.
The 2019 season was among the roughest of seasons in the 11-year MLB career of Jeremy Jeffress. The veteran reliever struggled to build shoulder strength in spring training, putting him behind the eight ball from the start. When he returned to the mound, his velocity was diminished, and he limped to a 5.02 ERA in 52 innings. He would hit the injured list once again near the end of August due to a strained hip. Upon activating him on September 1, the Brewers designated him for assignment. Jeffress would ultimately sit out the season’s final month, putting an end to a tough year.
One year later, Jeffress is anchoring the Cubs bullpen as their de facto closer. He has posted a superb 0.98 ERA in 18 1/3 innings and converted seven of eight save opportunities.
How did Jeffress turn his performance around so quickly? It is just the latest example of how the veteran has been able to remain in the Majors for over 10 seasons — he has constantly made adjustments and reshaped his plan of attack on the mound. Observe how his pitch usage has fluctuated throughout his career.
When he was drafted by the Milwaukee Brewers in the first round of the 2006 draft, Jeffress’s greatest weapon was his blazing fastball that could touch triple digits. Unfortunately, drug suspensions in 2007 and 2009 (self-medication for what was later discovered to be juvenile epilepsy) hampered his development, and difficulty controlling his blazing heater limited the number of opportunities he received in the Majors. In each of his first four seasons at the game’s highest level, he never pitched in more than 14 games.
Jeffress established himself in the Majors for good during his second stint in Milwaukee. After he was released by the Blue Jays early in the 2014 season, the Brewers signed Jeffress to a minor-league deal, and a strong performance in Triple-A Nashville earned him a call-up in July.
Jeffress was back in the big leagues, but this time he had more or less ditched his four-seam fastball in favor of a power sinker. The new approach worked, as he posted a strong 1.88 ERA, 2.57 FIP, 2.36 SIERA, and 61.5% ground ball rate in 28 2/3 innings. He would truly break out the following season, firing 68 innings as Milwaukee’s setup man. His sinker was still his money pitch, but his four-seamer made a return as he upped its usage to 27.6%. Those two fastballs paired with Jeffress’s nasty curveball to help him suppress hard contact and induce swings and misses. He finished the year with a 2.65 ERA, 3.22 FIP, and an 86 DRA-.
Jeffress put the four-seamer on the back burner once again in 2016, and he still managed to post a 2.33 ERA and save 27 games despite a career-worst 17.4% strikeout rate in a season split between Milwaukee and Texas. In 2017, however, things began to fall apart. The right-hander’s strikeout rate remained lower than usual, and his home run rate skyrocketed. He limped to a 5.31 ERA and 5.84 FIP with the Rangers before a trade back to Milwaukee began his third stint in the blue and gold. He lost one mile-per-hour on his average sinker velocity, and the formerly-effective pitch was crushed to the tune of a .419 opponent wOBA.
What did Jeffress do? He reinvented himself again. He regained his lost velocity, but he also utilized his arsenal differently than ever before. Jeffress threw his curveball more frequently than any other pitch (30.8%) for the first time in his career, threw the fewest percentage of sinkers (28.6%) since he first implemented the pitch in 2013, and brought back his four-seamer (24.8%). This enabled Jeffress to work north-south in addition to pounding hitters down-and-in with his sinker. He also used his splitter — a fourth pitch he began developing in 2016 with the help of Junior Guerra — as a change of pace to keep hitters off of his fastballs.
The result was a career year for Jeffress. His strikeout rate leaped to 29.8%, and he posted a minuscule 1.29 ERA in a career-high 76 2/3 innings. That workload appeared to catch up to him, however, as he struggled mightily in the postseason and dealt with the aforementioned shoulder weakness the following spring. He had fallen just as rapidly as he had ascended.
It was not looking good for Jeffress, yet here he is functioning as the cornerstone of the Chicago relief corps. It is not due to a return in velocity — in terms of stuff, 2020 Jeffress is more or less identical to his 2019 counterpart. His average sinker and four-seam velocity are still sitting at 93 miles-per-hour as they did last year.
The biggest adjustment Jeffress has made is returning to a pitch-to-contact approach to compensate for his diminishing stuff. In particular, he has done a significantly better job of locating his sinker after letting it bleed over the plate too often in 2019. This season, the pitch has limited hitters to a .184 wOBA, .277 xwOBA, and 83.3% ground ball rate.
Most importantly, Jeffress has regained the feel for his splitter. In 2019, he never felt comfortable with it and only threw it 9.1% of the time. The splitter is now his primary pitch, and at this point in his career, it is his best one. It has held opponents to a .181 wOBA and .241 xwOBA. They have struggled to square it up, managing just an 86 mile-per-hour average exit velocity, 31.6% hard-hit rate, and zero barrels against it. The split has also replaced Jeffress’s curveball as his go-to pitch with two strikes.
With his latest approach, Jeffress has seen average exit velocity and hard-hit rate rise, but that hard contact has not been nearly as harmful because it is being hit on the ground. His average launch angle against has dropped from 7.7 to 2.6 degrees, his line drive rate from 23.2% to 19.6%, and his ground ball rate has increased from 48.4% (a career-worst over a full season) to 54.4%. After yielding a miserable .393 expected wOBA on contact last season, Jeffress’s xwOBACON is down to .328 with the Cubs.
The downside is that the former Brewer’s stuff is not nearly as overpowering as it was in his heyday, and his new method for getting hitters out is more volatile than his previous ones. His strikeout rate has fallen to 17.6%, and his strikeout-to-walk ratio sits at an uninspiring 1.50, both of which are in line with his subpar 2017 campaign. As a result, there is a significant discrepancy between his sparkling ERA and his advanced metrics. However, most of the metrics agree that he has been better than he was last season.
On the whole, this version of Jeffress is better than the one we saw last season, but it is becoming increasingly evident that his days as an effective high-leverage reliever are in the rearview mirror. He is not a 0.98 ERA pitcher — not even close. He is benefitting from the kind of extraordinary luck (.152 BABIP) that is only possible in 18-inning sample sizes.
The best way to sum it up is by saying that Jeffress is in the midst of a transition to the twilight phase of his career. He is no longer a dynamite stopper like he was in Milwaukee, but rather a solid-but-unspectacular veteran middle reliever. He is due for a blowup outing soon and will likely have such outings from time to time, but for the most part, he should be able to get the job done adequately. That ought to be enough to extend his career for a few more seasons. Give Jeremy Jeffress credit — he has continued to work hard and reshape himself as a pitcher, and he is proving that he can still provide value.
Statistics cited are courtesy of Baseball Savant, FanGraphs, and Baseball Prospectus and are current as of September 12.