Marcus Semien Tries to Shake a Season-Opening Slump

Perhaps it was the batting order switcheroo, or maybe it was the minor league ballpark. Bumped out of the leadoff spot for the first time since last August 11, and down to fifth in the order for the first time during Bruce Bochy’s run as manager of the Rangers, Marcus Semien recorded his first multi-hit game of the season on Tuesday night in Sacramento. The 34-year-old second baseman went 2-for-3 with a three-run homer, a walk, a sacrifice fly, and four runs batted in against the Athletics — a much-needed positive sign given his season-opening slump.

Semien’s big night took place at Sutter Health Park, where the relocated A’s and their opponents have bashed out 5.4 runs per game while batting .270/.342/.466. Whether or not the venue was a factor, Bochy’s new lineup worked like a charm, as new leadoff hitter Josh Smith, new no. 2 hitter Wyatt Langford, and the slumping Jake Burger all homered for the Rangers as well. All of the shots were served up by 29-year-old righty Osvaldo Bido; Semien, who had already plated the Rangers’ second run with a first-inning sacrifice fly, crushed a middle-middle sinker 417 feet to center field to break open a 4-2 game in the fifth inning:

The homer was just Semien’s second of the season, and just his third extra-base hit. He entered the game batting .141/.209/.192 for a 17 wRC+, with all four of those numbers ranking among the bottom four among the 170 players with enough plate appearances to qualify for the batting title. His new and improved slash line (.160/.231/.247, 39 wRC+) now puts him among the bottom 10 qualifiers in those categories, but he isn’t close to being the worst on the team. Joc Pederson (.052/.141/.069, -37 wRC+) is having even bigger problems, including an 0-for-3 on Tuesday, but the Rangers don’t have nearly as much invested in him as they do in Semien, whom they signed to a seven-year, $175 million deal in December 2021.

Since the signing, Semien has been the linchpin of the Rangers’ lineup, combining power, speed, strong defense, and durability. In his three full seasons with the team, he’s averaged 161 games and twice led the majors in plate appearances and at-bats. He’s also made two All-Star teams and helped the Rangers win their first World Series, and over that span has ranked 14th in the majors in fWAR (14.8) and eighth in bWAR (17.5). By that latter measure, which includes his 7.7 bWAR in 2023 — tops among American League position players, but still behind the two-way work of Shohei Ohtani (10.0 bWAR) — he’s emerged as something of a stealth Hall of Fame candidate, given that he’s crossed the 40-WAR threshold for seven-year peak (40.6), a strong indicator of future election.

Throughout his 13-year career with the White Sox, A’s, Blue Jays and Rangers, Semien has proven to be something of a slow starter. He’s a career .239/.311/.392 (95 wRC+) hitter in March and April, compared to .257/.324/.448 (112 wRC+) from May through the end of the regular season. That’s a substantial difference; using our Splits Leaderboard tool and some Excel magic, I found it to be the 17th-largest gap among players since 2010 (a cutoff I chose out of thin air):

Semien ranks in the 81st percentile in this odd split, which isn’t even as extreme as that of his double play partner (Seager) but it may help to explain his comparative dearth of All-Star selections (three) relative to his excellence as a player. That thought occurred to me when I saw Francisco Lindor a few spots down the list with a 14-point difference (109 wRC+ in March/April, 123 the rest of the year) and no All-Star selections since 2019.

I don’t have any explanation for this oddity, but it persists and it’s apparently not that uncommon. Recall that Semien got off to a similarly bad start in his first year with the Rangers, hitting .157/.226/.217 (26 wRC+) through April following the lockout-abbreviated spring training of 2022, and while his final offensive numbers were unremarkable (.248/.304/.429, 107 wRC+), that was still good for a 4.4-WAR season thanks to his excellent defense. Still, after a stellar 2023 (.276/.348/.478, 126 wRC+, 6.3 WAR), he slipped to .237/.308/.391 (99 wRC+) with 4.2 WAR last year, so as with any 34-year-old player, it’s natural to wonder if he’s suddenly on the downslope of his career.

We’re early enough in the season that only some statistics are starting to stabilize, so the conclusions we draw shouldn’t be too firm, but no, I don’t think this is the beginning of the end for Semien. A few areas of his performance do stand out, with most of them merely a bit askew — but within the small sample, the downturn appears to be more than the sum of its parts.

Swing rates start to stabilize around the 350-pitch threshold, which Semien crossed on Tuesday night, so it’s noteworthy that he’s swinging more frequently than ever (51%), up even from last year’s full-season high (50%) and well above his career mark (45.4%). His 25% chase rate is a bit below last year, but still about three points above his career mark. In fact, Semien is a very disciplined hitter, one who scores well in Robert Orr’s SEAGER metric, which measures the quality of a hitter’s swing decisions. He’s been in the 90th percentile or above in each of his three full seasons in Texas, including the 94th percentile last year, but he’s down to the 84th percentile this year. That’s still impressive, in that it’s not like he’s suddenly up there taking desperate hacks, and it’s up from the 78th percentile, where he was entering Tuesday; his big game gave many of the stats within this piece a boost. That said, his 10% swinging strike rate is his highest mark since 2017, up half a point over last year and 2.2 points over ’23. Even if he’s making good decisions about what to swing at, they’re not quite as good as usual, and he isn’t connecting as frequently as he once did.

Semien’s swing metrics tell us he’s player who doesn’t have great bat speed. Even with the limited sample of late-season data from 2023, his 68.7 mph average swing speed placed in the 13th percentile, and he was down to 68.3 (ninth percentile) last year; this year, he’s at 68.6 (12th percentile). His 6.5% fast swing rate is very low (the major league average is 22.8%), but well above last year’s 4.2%, so if anything, one wonders if he’s swinging too hard on the rare occasions that he does dial it up. Both his squared-up and blast rates are down (from 30.7% to 27.3% for the former, and 9.8% to 6.5% for the latter), indicating his quality of contact is off. He’s never lit up the Statcast leaderboard; his barrel rates have been around league average, but his exit velocities and hard-hit rates have placed in the lower quartile. Here’s a look at his time with the Rangers:

As you can see, there’s not a tremendous difference between this year’s numbers and last year’s; Semien’s barrel rate is currently in the 52nd percentile, but his exit velo and hard-hit rate are in the 23rd and 15th percentiles, respectively. Despite the similar performances and the improved barrel rate relative to last year, his expected numbers — which he’s far short of, obviously — have fallen. I suspect that has a lot to do with his distribution of batted balls thus far, as it’s out of whack with his norms:

Semien is hitting far more grounders than usual, and he’s pulling them far more often. He’s batting just .207 on grounders, down from exactly .255 in each of the past three seasons (uncanny!). That would seem to explain part of what’s going on.

When a player in his mid-30s starts to struggle, it’s reasonable to wonder whether he’s having trouble handling fastballs. We’re getting into smaller samples within an already-small sample, but Semien is doing fine against four-seamers (.333 AVG/.500 SLG, compared to .243 AVG/.437 SLG last year). What’s odd is that he’s just 1-for-20 (.050) against sinkers, which he handled reasonably well last year (.273 AVG/.405 SLG), if not as well as the average major leaguer (.284 AVG/.421 SLG). Of the 18 sinkers he’s put into play, 12 have been grounders. He’s also a combined 1-for-24 against sliders and sweepers — both of which he struggled against last year — though of the 19 put in play, only eight have been grounders.

As to why Semien is hitting more grounders, and why fewer of those grounders are becoming hits, I can’t say, but it’s early enough that all of this could very well come out in the wash. We’ve seen Semien go through funks like this before, and with increasing frequency during his Rangers years:

The variations in Semien’s underlying metrics relative to recent years are small, but they’ve added up to a very large drop that, again, probably owes plenty to sample size and to the timing of our focus; we wouldn’t notice his slump nearly as much if it happened in August, four or five hundred plate appearances into the season. A season-opening slump inevitably raises questions regarding whether a player has suddenly gone over the hill with the flip of the calendar, but it’s understandable if psychological factors come into play as well. As former YES Network broadcaster Ken Singleton — an exceptional hitter who nonetheless endured some slow starts — used to say, it’s no fun to look up at that scoreboard and see that you’re still “stuck on the interstate” with a batting average that starts with a 1 (as in, looking like a capital I).

While the Rangers are off to a 14-9 start despite a -12 run differential, they entered Tuesday ranked 25th in the majors with an 84 wRC+ (.220/.274/.363), and 29th in scoring (3.05 runs per game). The time was ripe for Bochy to shake things up.

“I don’t have any say right now, until I start getting back to doing what I do,” Semien said when asked about the lineup prior to the game. “I have no say, so that’s where I’m at. I hit some balls hard last game. There’s certain days where I come back into the clubhouse after the game thinking that day could have been a lot different on the stat sheet, if I found the gap here or there. But it hasn’t been that way right now. It’s frustrating. But like I said, the Rangers are playing well. That’s what matters.”

Maybe the downscaled venue had something to do with Semien’s big night. “We all hit well in the minors,” he said afterwards. “So let’s just pretend it’s the minors. That’s how we all got here, maybe that’s why.”