Marcus Semien, Now More of a Shortstop
Last year, there wasn’t a worse defensive shortstop in the big leagues than Marcus Semien. That’s what the numbers say — traditional and advanced — and it’s also what observers thought as they watched the Oakland A turn in Es with his arm and his legs. It was fair to ask if he’s a shortstop at all.
Then Ron Washington joined the fold, and the shortstop started working with his infield coach. Every day. Before anyone else hit the field, there were Semien and Washington, with their tools, running through the drills.
The turnaround has been remarkable, and deserves more attention.
First up is the small glove. It looks like a regular glove, but — and hopefully the image here adequately conveys this — it’s just barely bigger than the shortstop’s hands.
With the small glove, you focus on up-close work. “You start off close hop and work on short hops and isolate your hands,” Semien said. Shorter fingers means that you really have to watch that ball into the palm of your hand. Less glove means less of a safety net.
Then comes work with the flat glove.
With the flat glove, the emphasis is still on the palm, but there are different mechanics. “You really need to catch the ball out in front on that glove or it will bounce off,” the shortstop said. “You’re really pushing through the ball and then give a little bit at the end, so the ball can’t go anywhere.”
Both of these exercises require calm hands throughout the process — the sort of calm hands that can lead to fewer errors. This year, Semien’s double-play runs are about the same and his range numbers are even down. Most of his improvement has come from going from -12.5 runs on errors to 0.5 this year.
There were other adjustments. “I hold my glove wide open now, before I would use a smaller glove and didn’t really know how to spread it out,” he said. “Now I’ve switched to a bigger glove and continue to do the drills that we do in order to get more consistent.” That work with alternative gloves has allowed him to use a larger glove more efficiently.
Last year, Semien recorded 17 fielding errors over the course of the season. He’s cut that down to two so far this season. If 17 were his true talent, you’d have expected five by now.
And then there’s the throwing. What does Semien do to improve that facet of his game? “Throw from every spot on the field,” is the simple answer. “Just work on getting the arm speed up and throwing from different angles when you need to.” But also the mechanics of the throw are important. “I think about my lead foot direction a bit, but more about the length of my stride,” Semien said. “It helps you get your backside into your throw. Last year, I was throwing and not getting much behind it and relying on my arm. And my arm is not at its highest strength if I don’t have any back side.”
Last year, Semien had 18 throwing errors for the season. He’s cut that down to one so far this season. If 18 were his true talent, you’d have expected five by now.
His work has had some impressive overall results, of course.
Not only has he had some highlight-reel moments, but he’s improved more than just six other up-the-middle defenders in baseball this year. That’s important because up-the-middle defenders get many more chances than other positions, and their defensive stats are more robust for it.
| Name | Pos | Plays | UZR | UZR/150 | 15UZR/150 | Diff |
| Kevin Pillar | CF | 83 | 10.3 | 40.4 | 16.0 | 24.4 |
| Dexter Fowler | CF | 66 | 4.6 | 17.5 | -1.9 | 19.4 |
| Jacoby Ellsbury | CF | 56 | 0.6 | 12.8 | -5.6 | 18.4 |
| Brandon Crawford | SS | 83 | 8 | 29.5 | 11.9 | 17.6 |
| Neil Walker | 2B | 76 | 1.6 | 6.1 | -8.8 | 14.9 |
| Freddy Galvis | SS | 90 | 4.4 | 14.2 | 0.6 | 13.6 |
| Marcus Semien | SS | 94 | 1.7 | 2.5 | -10.4 | 12.9 |
| Brett Lawrie | 2B | 86 | -0.7 | -3.2 | -15.8 | 12.6 |
| Xander Bogaerts | SS | 80 | 3.5 | 13.5 | 0.9 | 12.6 |
| Mike Trout | CF | 90 | 2.7 | 9.7 | 0.3 | 9.4 |
You’ll notice that some of those players were good and just got better, which isn’t really what this shortstop did. Another way of saying it is: nobody was more of a defensive liability last year and turned it around in a bigger way than Semien has.
Semien knew that there were haters. “I tried not to listen to outside voices and rely on the support within the clubhouse,” he said of working through the criticism last year. “I love the group we have here.”
He knew that there was a lot of work to do to improve his footwork, his glovework, and his throwing. “There’s a lot of things you can put into it,” Semien agreed. “That’s why I work on it every day, because there’s so much to work on.”
“I want to be the best shortstop I can be,” Semien said. And he’s still putting that work in every day, just after lunch, while the rest of his teammates are just filing in.
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.


Crazy to see Pillar at the top of that table as the most improved up the middle. Dude plays with zero regard for his body.
Mike trout on the list is crazier to me, cuz ya know he was already mike trout.
Trout is obviously great, but the original point is more impressive. Mike Trout has improved enough to make this list, yet his improved 2016 self is still below 2015 Pillar in terms of UZR/150. Despite that, Pillar has still somehow managed to improve so much over 2015 that he leads the list in improvement.
That improvement to +9.7 for Trout is more of a regression to his 2012/2013 self though.
Look closer at Trout and UZR in CF. Perception still seems to outwork numbers with him
His first year he robbed a bunch of homers. He was also really fast so I think that combo skewed people to think he was an amazing cf.
I thought trout was more impressive because he was 8 and 9 war with basically negative d
great article, watching marcus this year vs. last has been night and day.
that flat glove looks more like a punching mitt for boxing, not something remotely related to baseball.
I liked semien when he was on the sox. I think Ian desmond is a good peak comp.
5 years of this guy, for one year of Shark when the Sox weren’t going to be contenders…
Hahn has done a pretty good job, but that trade was still beyond stupid on its face when it was made. And now they’re playing Rollins and Saladino…
The White Sox never viewed Semien as their short stop of the future, and technically they got 1 2/3 years of Shark for him.
Tim Anderson was always viewed as their blue chipper, and their SS of the future.
I liked/like Semien as well, but it’s hard to bash the trade; especially by stating they weren’t going to be contenders. That certainly wasn’t the expectation people had for this team going into last year. Hindsight bias makes it easy to say it was a mistake – especially given how bad Samardzija was – but Semien was hardly a sought after piece. He was considered the 5th best prospect in a very weak farm system. The White Sox never viewed him as a SS either.
No they got shark before last off-season. 1 yr, they also have up chris Bassett who is certainly a big league pitcher despite the tommy John.
Edit:
Yeah, I’m an idiot. For some reason thought it was a mid-season acquisition. He was so bad for the Sox I thought he was there forever.
I believe you’re thinking about the Addison Russell for Shark trade, which happened when Shark had more like 1.6 years of control left.
They also got Josh Phegley, a legit backup catcher. They also got Rangel Ravelo, who will probably get some major league at bats, even if he’ll probably never be an everyday player. That trade was highway robbery.
If Samardjiza would have thrown the ball for the White Sox like he is for the Giants, the trade would be have been highway robbery in favor of the White Sox. We needed a righty- starter entering 15′, took a shot, and it didnt work. I dont care that Semien and Phegley aren’t on the Sox roster right now. We wouldn’t be any better or any worse without them. Those guys aren’t impact guys. And if Semien never works with RW, who knows what kind of player he would be as of today. Oakland won that trade, but it isn’t anything to lose sleep over. Only thing that sucks about is, Semien seems to have legit power (but I like a Saladino/Rollins platoon more anyway). Had Shark won 15 last year and we contended for the wildcard like the front office thought, everyone would be singing a different tune.
Strange that Semien improved under Ron Washington’s tutelage, because looking at his statistics Washington was pretty awful defensively during his career as a player
Of you look at when he was in the majors though, he spent most of his peak defensive years in the minors. So he may have been really good when he was younger, but he didn’t get regular time in the bigs til he was 29.
Eric Chavez credits his six Gold Gloves to Wash’s instruction.
Can someone fill me in on whether these defensive range ratings factor in the use of shifts?