Last week, we viewed Fly Outs as a defensive statistic for outfielders and saw that while it can show that a player has a lot of range, it does not offer a lot of opportunities to make fair comparisons between different players because of factors that outfielders can’t control, such as Park Factor, size of the outfield they play in and the pitching rotation they play behind.

This week, we’ll look at a statistic that better allows baseball fans to compare players on defense, Ultimate Zone Rating (UZR).  For those looking for an explanation of how to calculate UZR, check out the “How to calculate UZR” section of Alex Remington’s blog.  What makes UZR a helpful and worthwhile statistic is that it measures a player’s defensive ability compared to league average.

From FanGraphs

UZR is expressed in terms of runs so UZR also helps display how many runs a player prevents himself and the defensive impact he has on his team.  It is calculated by Baseball Info Solutions which tracks where every ball is hit, how hard it is hit, what type of hit it was (grounder, line drive, flyball, etc.) and what percent of the time did a player at that position make a play on the ball.  The field is divided into 78 zones and if a player is able to reach more balls hit of different play types, their UZR will be higher than league average.

While UZR is a great way for fans to evaluate a player’s defensive abilities compared to league average, there are some flaws.  John Dewan, creator of Baseball Info Solutions (BIS) said last March at the SABR Analytics Conference in Phoenix that we are only 60% of the way in the defensive metrics field and there are many improvements to be made in the near future.  On Thursday when we do our player analysis of Derek Jeter and do some comparisons, we will look at UZR/150 which is allows for more effective and accurate evaluations.