With and without Aramis Ramirez
1 Comments Published by Colin Wyers on Monday, April 21, 2008 at 11:31 AM.
Consider this a lark with data; I wouldn't consider the conclusions definitive, or even necessarily meaningful. It's at least thought provoking.
First, I cobbled together a fascimile of a zone rating system based upon the work of Sean Smith on TotalZone. Let me be clear here: my zone rating system is probably the worst zone rating system in existence. If you want a Zone Rating system based on Retrosheet data, TotalZone or SFR are vastly superior; UZR and PMR are better still. And my system - let's call it SZR, for "Stupid Zone Rating" - only rates shortstops, making it even more, well, stupid. Or "special," if you're worried about hurting its feelings.
Here's how it works:
- Shortstops are given credit every time they record an out or fielder's choice on a ground ball.
- An "opportunity" to make a play is assigned for errors, and half of all ground ball singles hit to left and center field.
Stupid Zone Rating is simply Outs divided by Outs plus Opportunities.
So why invent the worst possible zone rating system? Because it lets me play around with the data a bit. In this specific case, what I wanted to know was simple. Aramis Ramirez had easily the best defensive season of his career last season. He also missed no small amount of playing time, which gives us a healthy amount of "non-Aramis" opportunities to compare to.
What I was curious about was, did A-Ram's big defensive season have an effect on the Cubs shortstops?
The average SZR of a shortstop from 2004-2007 was .766. During that time, the average SZR of Cubs shortstops when Ramirez didn't play was .801; when Ramirez played, the average SZR of Cubs shortstops was .761.
Now, we'll drill down to 2007. When Ramirez played in 2007, Cubs shortstops averaged a .762 SZR; when Ramirez was out of the lineup, the Cubs averaged a .797 SZR.
I have to go to my actual paying job now, so I'll leave figuring out what that data means as an exercise to the reader. The full spreadsheet is available to peruse.
(The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at 20 Sunset Rd., Newark, DE 19711.)
Labels: Aramis Ramirez, Baseball, Chicago Cubs, Defense, Mark DeRosa, Ronny Cedeno, Ryan Theriot
Could we compare this to other 3B on the Cubs or other teams? That might lead to more information being derived from this. Either way, it would appear that ARam takes a few plays away from the SS.