In 2015, the A’s acquired Marcus Semien in a trade with the Chicago White Sox.  Despite reservations from what seemed like the entire world, the A’s elected to start him every day at shortstop.  The early results were atrocious.  He was by far the worst fielder in the game, and people began to wonder if he’d put up a historically bad season.  In an effort to reverse this process, the A’s hired fielding guru Ron Washington midseason.  Washington was famous for making Miguel Tejada into a decent fielder and Eric Chavez into a modern-day Brooks Robinson.  As an A’s fan, I wanted to know if Wash’s help was really affecting Semien at all.  The problem was that, as far as I could tell, advanced fielding statistics aren’t available in split fashion.  I couldn’t compare first-half to second-half, or get the last three weeks of data, etc.  I really had no way to know if Semien was getting better other than to take mental notes, and then re-check the stats a week later.

The Semien Report is an effort to remedy this for fans like me.  Every week, I’m going to pull UZR, DRS, and DEF from Fangraphs for each fielder with at least 10 IP at each position on the season.  From there, I’ll compare those statistics to the previous week, and in time their numbers from four weeks prior, in an effort to find out who seems to be changing their course, defensively.  There are, of course, some caveats:

  • I’m not going to bother with pitcher and catcher.  Pitcher because it’s already a small sample size I don’t want to parse anymore, and catcher just isn’t evaluated very well by these statistics.
  • Advanced fielding metrics take a long time to start to mean anything, so take this with a whole salt lick.  It’s very likely that any changes seen for the first few months are just noise, but it’s possible there’s something meaningful there.
  • Because I’m breaking down by position, I’ll miss out on utility guys or multi-position wonders.  I’m not sure if there’s a great way around this.

That said, here are some potential answers that might be gained from questions being asked this year:

  • Will Hanley Ramirez provide decent defense at first base as he learns the position, or is he doomed to be negative forever?
  • Is Ian Desmond best suited to shortstop, or have the Rangers found themselves a plus outfielder on the cheap?
  • Will any of the hot newcomers at shortstop, like Francisco Lindor or Carlos Correa, fade down the stretch of their first full season in the bigs?

I won’t provide full data this week; tune back in for the first real installment.  I’ll tide you over with some fun facts, though, from the first week (data pulled Monday Night, 4/11):

So tune in next week, and thanks for reading!

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10 Responses to “The Semien Report: Introduction”

    • Andrew Patrick

      Beats me. I tried to ask Twitter, but they were unsure. Until then, we’ll get DRS and DEF results.



  1.  The Semien Report: Week 2, Adonis and Adams Edition | Banished to the Pen
  2.  The Semien Report: Week 3, Bruce and Rickard are Bad Edition | Banished to the Pen
  3.  The Semien Report: Week 4, Good Eaton Edition | Banished to the Pen
  4.  The Semien Report: Week 5, Grandy/Melvin 2007 Edition | Banished to the Pen
  5.  The Semien Report: Week 6, NL West the NL Best Edition | Banished to the Pen
  6.  The Semien Report: Week 7, Bad Eaton and a Pillar of Hope | Banished to the Pen

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