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.

Biggest Defensive Improvements Up the Middle, 2015-2016
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.

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7 years ago

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.

7 years ago
Reply to  waitzsauce

Mike trout on the list is crazier to me, cuz ya know he was already mike trout.

7 years ago
Reply to  JediHoyer

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.

7 years ago
Reply to  steex

That improvement to +9.7 for Trout is more of a regression to his 2012/2013 self though.

7 years ago
Reply to  Walter

Look closer at Trout and UZR in CF. Perception still seems to outwork numbers with him

7 years ago
Reply to  Alex

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.

7 years ago
Reply to  steex

I thought trout was more impressive because he was 8 and 9 war with basically negative d