Friday, February 7, 2014

Saber-Series: Part 2--Defense

Okay so defense is a whole other ballgame, its known within the Saber community that defense is not as quantifiable as opposed to offense. Nonetheless, there are some very solid defensive metrics out there that I will highlight today. Take for example Manny Machado, Machado posted a 6+ WAR last season (See Saber Series Part 1) and most of which came from his other-worldly defense. Defense has often been underrated by the old school but it's one of the main components of a players overall contribution to their team and should be treated as such. I also need you to remember that defensive statistics are not as accurate as their offensive counterparts, in addition there is also a lot less reliable stats and therefore this post will be shorter than Part 1 but the information is still vital and I will highlight the stats I will use most in my writing.  Below are some of the primary defensive statistics.

DRS (Defensive Runs Saved): DRS puts players fielding abilities in the perspective of saving runs above or below league average. It measure how many runs a player saved or cost his team based on his ability. 0 is average and 15+ is Gold Glove Caliber. The calculation is quite complicated for this stat but below I will include an explanation from Sports Illustrated:

“…as I understand it, the numbers determines (using film study and computer comparisons) how many more or fewer successful plays a defensive player will make than league average. For instance, if a shortstop makes a play that only 24% of shortstops make, he will get .76 of a point (1 full point minus .24). If a shortstop BLOWS a play that 82% of shortstops make, then you subtract .82 of a point. And at the end, you add it all up and get a plus/minus.” (Joe Posnanski, Sports Illustrated)

UZR (Ultimate Zone Rating): Is by far the most popular and widely used advanced defensive statistic out there. Most people describe it as a more complicated version of DRS that takes other things into account, but behold, that means nothing to you guys and gals. UZR attempts to put a run value to defense, it does this by looking at a variety of factors to determine a players ultimate defensive contribution to their team. The UZR takes into account the following:
● Outfield Arm Runs (ARM) – The amount of runs above average an outfielder saves with their arm by preventing runners to advance.
● Double-Play Runs (DPR) – The amount of runs above average an infielder is in turning double-plays.
● Range Runs  (RngR) – Is the player an Ozzie Smith or an Adam Dunn? Do they get to more balls than average or not?
● Error Runs (ErrR) – Does the player commit more or fewer errors compared with a league-average player at their position? (Courtesy of FanGraphs)
UZR is measured on the same scale as DRS, with 0 being average but remember that UZR tends to be more reliable and most often used. 

Def Eff (Defensive Efficiency): This statistic is used to measure a whole teams offense and is calculated as a percentage to represent the plays which were converted to outs by a teams defense. Average Def Eff falls in the .710 range and the team is considered above average if their Def Eff rating is above .730. 

FRAA (Fielding Runs Above Average): This stat differs from the other defensive stats because of the philosophy behind its calculation. This stat, which is exclusive to Baseball Prospectus, ignores the zone-based metrics because of the biases present and uses play-by-play data to calculate its numbers. The number it spits out is the number of plays made by said player above average for another player at said position. The average FRAA rating is about 0.5, in 2013 Manny Machado had a 28.4 FRAA. 

Well believe it not this is where our lesson ends today, I know it seems like half a day but like I said defense it much different than offense I just wanted to cover the prominent ones. Study up and keep these in mind because everything I am teaching will be used in my writing. Tip: if you cant find a particular stat on one website, search the other. Often times I use both FanGraphs and BP. If you haven't checked out Part 1 of Saber-Series yet be sure not to miss out, click here! Check back this weekend for some of my first official articles and Part 3 of Saber-Series!

All stats and some dialogue provided courtesy of FanGraphs and Baseball Prospectus. 

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