Regression is such an ugly word. Why can’t players just stay elite forever after a breakout? Thanks to innovations in mathematics and physics, we have a wealth of analysis at our fingertips to assess whether a player’s recent performance is sustainable or not.
Expected stats such as xwOBA, xAVG, xSLG and xwoBACON (mmmm, BACON) are readily available to dissect hitters in the league and find balance in their performance. There is no absolute truth in the expected statistics which makes them cut and dry. Gray areas exist even when all data is tracked and processed.
Fast players can regularly outperform their expected stats, while slow players can regularly perform below their expected stats. Furthermore, some players have such a hold on the parks that they can force a baseball into the stands with their own repetitive tendencies, despite poor expected power numbers (see: Paredes, Isaac).
The players mentioned were all lucky in one way or another. Some of them may continue to reap the success of variance, but regression applies to all… eventually.
3B Junior Caminero (TB)
The Rays are moving back to Tropicana Field after playing one season at George Steinbrenner Field, the Yankees’ Spring Training home. This move doesn’t make Caminero unviable, nor does it prevent him from continuing his breakout, but it should give pause to those eyeing a 45 HR season.
Caminero didn’t perform much better than his peripherals on StatCast, but there is reason to worry when he goes from one of the best hitting environments in the league to one of the worst. As far as we know, Tropicana Field’s park factors should remain unchanged despite a recent renovation due to Hurricane Milton.
Caminero posted an average exit velocity and expected slugging percentage among the league’s best in 2025 and was able to replicate that in 2026. However, several of those balls that were home runs in 2025 could be turned into doubles. The young star 3B could improve and make me eat my words. However, with draft costs ranking in the top 20 in most formats, it’s tough to pay for someone who likely benefited from a one-time park change (see: Blue Jays in 2021).
SS Trea Turner (PHI)
The Phillies will field roughly the same team in 2026 and hope their veterans can continue to serve on offense. For the first time since 2021, Trea Turner is having his best offensive season since 2022 with an average above .300. He is perhaps the most underrated player in the league over the past decade, and it pains me to include him on this list.
Turner is not yet geriatric at age 32 (33 in June), but he is creeping toward a point where he will no longer be in the 100th percentile of MLB sprint speed. Since he was first drafted in 2015, Turner has ranked in the 100th percentile for seven of his 11 seasons. He wasn’t for all four seasons, spending three seasons in the 99th percentile and one season in the 96th percentile (2024).
Sadly, Turner isn’t getting any younger (I had to double check). Sprinting speed is much more difficult to maintain compared to power as players reach their mid-thirties. His bat started degrading as early as 2025 with his lowest barrel percentage since 2018 and lowest xwOBA since 2015. He outperformed his .270 xAVG with a .304 AVG and his .410 xSLG with a .457 SLG. He can continue to exceed his expected stats, but the speed can only sustain the flagging power for so long.
SS Geraldo Perdomo (ARI)
Geraldo Perdomo was one of MLB’s more valuable players in 2025. He was fifth among all hitters in fWAR (7.1) and 12th in wRC+ (138). This season was a legitimate breakthrough for Perdomo, but to what extent? He outperformed his expected average by .012 and his expected slugging percentage by .038. Neither indicates a massive decline, yet its history is still ominous.
Perdomo slashed .235/.327/.330 in 1,420 plate appearances over his first four MLB seasons. Last season he slashed .290/.389/462. The elite plate discipline is durable, and his power may have taken a step further at age 25. Perdomo is in his athletic prime, which makes a breakout reasonable. Either way, I can’t shake the feeling of regression.
He was never this good in the lower minors at 19 or in the high minors at 21! I want to like Perdomo for his all-around game. Unfortunately, I’ll be staying away to see if the outbreak from afar was that real… at least for another season.
1B Josh Naylor (SEA)
The Mariners traded for Josh Naylor last season and a funny thing happened. HE STOLE 30 BASES PER SEASON!! Josh Naylor stole a total of 25 (!!) bases through his first 598 MLB games. He stole ten in 121 games two seasons earlier, but only six in 152 games in 2024.
Naylor started the season with 11 steals in 93 games with the Guardians. He was on pace for 19 total in a 162-game season, but still managed to steal another 19 in 54 games with Seattle. The 5’10” 235lbs Naylor has a third percentile sprint speed. He doesn’t steal 30 games a year even though he is the best in the world at timing jumps.
Additionally, Naylor scored well above his expected stats last season. His .271 xAVG and .462 xSLG are both behind his .295 AVG and .462 SLG. Naylor’s luck was great as a hitter in Seattle, even more so than in Cleveland, where his xwOBA and wOBA were identical. Expect the bat to simmer this season, as Seattle is MLB’s worst park for left-handed hitters over the past three seasons.
VAN Jurickson Profar (ATL)
After testing positive for performance-enhancing drugs and serving an 80-game suspension, Jurickson Profar returned to the Braves’ lineup without losing a step. He provided 14 HR, 56 runs, 43 RBI, 9 SB and a 122 wRC+ in 371 plate appearances. This followed a season in which Profar posted a career-best 24 HR in 158 games with a 139 wRC+.
Profar was once a top talent and has a certain talent. However, his career .321 wOBA and 2025 .325 xwOBA are much closer to who he is than the .346 and .365 wOBAs of the past two seasons. He is able to post good stats at the heart of the Braves’ offense with his plate discipline and occasional power, but at the expense of batting average. Profar’s .230 xAVG and .390 xSLG in 2025 should foreshadow his raw stats in 2026.
#hitters #due #negative #regression