In the Bill James Gold Mine 2010, this note appears in the Cardinals section:
“Starting 95 games at shortstop for the Cardinals, Brendan Ryan was 25 plays above average as a defensive shortstop – that is, he was +25 in John Dewan’s Plus/Minus System. In those 95 games, the Cardinals went 58-37 and allowed 3.43 runs per game. When someone else started at shortstop for the Cardinals they went 33-34 and allowed 4.68 runs per game.”
While largely coincidental, there’s some truth behind the numbers. Taking into account his range and his performance on double plays, Brendan Ryan totaled 20 Runs Saved last season while other Cardinal shortstops cost the team 6 runs (-6 Runs Saved). It’s apparent that with Brendan Ryan on the field, the Cardinals were a better defensive team than without him.
These stats should be taken with a grain of salt. When a team’s regular starter starts 154 out of 162 games, you can’t rely on the eight other starts to tell you anything meaningful. Applying that disclaimer, however, we can look back at 2009 to see which players were most crucial to their team’s defense, coincidentally or not. With apologies to both Paul David Hewson and fellow TMI Blog contributor Tom Tango, here are the With or Without You defensive leaders of 2009 (minimum 1/3 of team’s games started):
With or Without You
Largest difference in team runs allowed by position
You can see why the Yankee faithful might believe Mark Teixeira dramatically improved the team’s defense- in the twelve games without Teixeira in the starting lineup, the Yankees allowed nearly 1.5 more runs per game.