Writing about playoff trends is risky business. The entire postseason, to this point, comprises 36 individual games. In the regular season, the league hit the 36-game mark on April 2. If you looked at the stolen base success rate that early into the season — 88% through those first 36 games — you’d have thought we were in for an absolute free-for-all under the new rules. Writing about individual players is even more dangerous. The most that anyone has played in this postseason is 13 games; 13 games into his season, Matt Chapman led the majors in WAR. Jorge López hadn’t given up an earned run. No one on the Rays knew what it felt like to lose a game. Mookie Betts had a 13-game stretch in mid-April where he slashed .184/.298/.306. Shohei Ohtani had a .538 OPS over 13 games in mid-May.

Nevertheless, we can’t not write about the postseason. It’s the postseason! The sample size will always be small, but we must try to make sense of it anyway, to find meaning in the small sample weirdness. And on that note, it’s time to talk about Marcus Semien.

Through 58 postseason plate appearances, Semien has a 43 wRC+. Out of 36 players with at least 30 PA in the playoffs, that ranks fifth-worst, ahead of only Martín Maldonado, Jeremy Peña, Evan Longoria, and Johan Rojas, hardly the kind of company that the two-time MVP finalist usually keeps. Along with Longoria and Rojas, Semien is the only qualified hitter with a wRC+ below 100 in all three series thus far; his best performance came in the ALDS, in which he slashed .214/.267/.286 with a .247 wOBA and a 50 wRC+. After finishing fourth in the AL in extra-base hits during the regular season, he has just two in the playoffs. He has yet to hit a home run. His .038 isolated power would make even Myles Straw shake his head. On top of that, he hasn’t stolen a base either, although that probably has something to do with his .276 OBP.

Every hitter goes through cold streaks, and Semien is no exception. Indeed, the veteran has a bit of a reputation for inconsistency; he has bounced back and forth between “MVP candidate” and “league-average hitter” each season since 2019. Even this year, when he was one of the most reliable players in the game throughout the regular season, he had some stretches like this:

Semien’s postseason wOBA is .237. Every point below the dotted red line represents another 12-game stretch over the past three seasons when he was equally unproductive. It’s not common, but it happens, and there’s certainly no need to sound the alarms. After busting out of his latest cold stretch around game no. 400 on the graph, he hit for a .371 wOBA over the rest of the season.

What’s more, Semien is showing several classic signs of hard luck this October. His .217 BABIP is 70 points below his career average, even though his line drive rate is way up at 26.1%. His pull rate is low, but it’s only down on groundballs, so if anything, you might have thought his BABIP would be higher than usual. On top of that, he has walked as many times as he has struck out, and his 10.3% strikeout rate is the second lowest in the postseason (min. 20 PA).

The Statcast expected metrics also offer reason for optimism, though you have to dig a little deeper to find it. Semien’s xBA, xSLG, and xwOBA are all significantly higher than his actual stats, but they’re still not particularly inspiring:

But there’s some more small sample size weirdness going on here. Stats like batting average, slugging percentage, and even wOBA work with a limited number of inputs. Regular old batting average is a binary system; every input is either “hit” or “not a hit.” Meanwhile, slugging percentage and wOBA only differentiate between types of hit, not quality of hit. In other words, a base hit off the scoreboard and a dribbling infield single are equally valuable. In the same vein, an out is always just an out, whether it’s a scorching liner or a can of corn.

Expected stats are a whole other animal. The difference between a base hit off the scoreboard and an infield dribbler can be enormous; so can the difference between a hard-hit line out or a lazy pop fly. Thus, a few pop outs or weak grounders can tank a batter’s expected stats in a small sample size, and a couple of no-doubter home runs can make them shoot back up. In Semien’s case, it’s the former. He has put a few too many non-competitive balls in play, and that lousy contact is overshadowing all the high-quality contact he has made.

Of the 46 balls Semien has put into play, 13 have had an xBA below .020 – just over 28%. Similarly, 20% of his batted balls have had an xBA below .010. In the regular season, those percentages were just 15% and 11%, respectively. There’s no defending that kind of contact; there’s no such thing as “bad luck” on balls in play when the balls in play are hit so poorly. But at the end of the day, one out is just one out. A popup isn’t any worse than a routine groundout, even though the popup is going to have a harsher effect on a hitter’s expected stats. More to the point, being a good hitter is more about the high-quality contact a batter can make, rather than the low-quality contact he doesn’t make.

And Semien is still making high-quality contact at a similar rate. His line drive rate is up. He’s pulling balls in the air as much as ever. On all balls in play with an xBA above .020, he has a higher xBA and a similar xwOBA as he did throughout the year. About 26% of his batted balls have had an xBA over .500, compared to 24% in the regular season, and 9% have had an xBA over .800, compared to 10% in the regular season. He’s still making good contact, but it’s harder to see that, because his poor contact has been worse than usual.

Semien should be just fine, but it’s worth looking into all that low-quality contact a little further. The biggest problem has been the combination of popups and weak fly outs; so far, nearly one-third of his fly balls haven’t gotten out of the infield. Here’s a compilation of all his batted balls with an xBA below .020, split into two videos because MLB Film Room caps any supercuts at 10 clips:

As you might have picked up, most of those pitches were fastballs, and nearly all were in the strike zone. They varied in terms of speed and exact location, but ten of 13 were four-seamers, and all but one landed in the zone. Eight were even in the heart of the strike zone, as defined by Baseball Savant.

Four-seam fastballs aren’t a new problem for Semien. Over the past two years, the only offering he has a worse wOBAcon against in the strike zone is the sweeper, and the sample size is much smaller for that pitch:

Two of the three teams Semien has faced in the postseason took a four-seamer–heavy approach. The Rays threw him four-seam fastballs on 18 of 32 pitches, and the Astros tossed him a four-seamer 43.4% of the time. Interestingly, Houston lived outside the zone against him, giving him very little to work with, but that may be why he swung so aggressively when he did get a fastball in the zone. The Orioles, for their part, leaned on the slider, throwing him one of the two breaking balls for 21 of 56 pitches. He did well to lay off sliders and sweepers, swinging only seven times (33.3%) and chasing only thrice (21.4%). Perhaps after so many breaking balls, he was a bit too aggressive when he saw a fastball down the middle.

Opposing teams have done well in executing their various plans against Semien so far in the playoffs. At the same time, he’s still drawing his walks, making frequent contact, and hitting the ball with authority as often as ever. He has created his own bad luck with so many popups, but he’s also been the victim of some good defensive plays and some well-positioned fielders.

Semien was arguably the most valuable player on the Rangers throughout the regular season, playing all 162 games and leading the team in WAR. Through 12 games in the playoffs, he has been the least valuable player on the roster. But postseason narratives can change in the blink of an eye. Look no further than Nick Castellanos, who had the highest OPS among qualified hitters in the NLDS and the lowest OPS among qualified hitters in the NLCS. Perhaps the Diamondbacks have a master plan of their of own to hold Semien at bay, but it’s just as possible he’ll turn a few of those popups into home runs, turning around his postseason narrative at the same time.