We reference Defensive Runs Saved in many of our blog posts. But what exactly is this stat?
Defensive Runs Saved
Defensive Runs Saved (created by the stat-tracker Baseball Info Solutions) measures the value of a player’s defense compared to his peers.
This is calculated in various ways, depending on the player’s position.
For all players, the primary component how often a player turns batted balls into outs.
Players who turn a higher percentage of batted balls into outs than their peers receive a higher rating than those who don’t.
For example: if Tampa Bay Rays third baseman Evan Longoria fields a ball hit down the third base line that (based on video review) is historically turned into an out only 20 percent of the time, he receives an 80-point credit (100-20).
If the ball rolls down the line, and the batter is safe, Longoria is debited 20 points for failing to make the play.
Credits and debits are added over time to accumulate a total for each player in the field.
Those are added to other components, such as …
For corner infielders
How often do they turn bunted balls into outs?
For middle infielders
How effectively do they convert double-play chances into double plays?
How effectively do they deter baserunners from taking an extra base (first to third on a single, second to home on a single, and first to home on a double) when they field a ball?
How often do they rob opposing hitters of home runs?
How effectively do they prevent stolen bases?
How effective is a catcher in keeping his staff ERA down?
There are other credits and debits for fielders based on video review of plays classified as "Good Fielding Plays" and "Defensive Misplays" though the rewards and penalties for those are small compared to what they receive for turning batted balls into outs.
If a fielder rates major-league average at his position, he will finish with zero Defensive Runs Saved.
Leaders and trailers
In 2012, 20 fielders finished with at least 15 Defensive Runs Saved and 40 finished with -10 Defensive Runs Saved or fewer. Those represent the game's best and worst fielders.
Defensive Runs Saved totals can be found at Baseball-Reference.com