3B Success! What’s up with new Defensive Stats?

So far this season, first-time third baseman, Jose Lopez, is doing more than just holding down the fort at the hot corner. In fact, according to Fangraphs UZR stat, he has saved his pitchers more runs than any other major leaguer at any position. And this isn’t the tiniest of sample sizes, seeing as he’s made 74 successful plays.

Defensive metrics are still evolving, but considering Baseball-Reference’s Total Zone Rating also ranks Lopez on top of the list defensively, it’s safe to say he must be doing something right.

The conventional method of measuring a fielder is looking at his fielding percentage, in addition to his “web gems.” This leads us to believe that players like Nate McLouth and Derek Jeter are well above average at their respective positions.

But take the following two plays into account. The batter smokes a hard line drive into the hole between third and short, about 8 feet from where the shortstop usually plays. Shortstop A dives to knock the ball down, springs to his feet and just misses throwing out the runner by half a step. Shortstop B anticipates the grounder, slides over at the crack of the bat, and calmly throws out the batter at first. Neither player is assessed with an error, as no scorekeeper would give shortstop A’s effort an E6, but there is an obvious difference in ability. That ability can be measured in better ways than fielding percentage.

Zone Rating-type defensive metrics divide the field up into pieces. When a player makes a successful play in a given sector of the field, he is credited as such. Once enough data is accumulated, it becomes apparent which players can and can’t cover ground to make plays outside their “zones.” This goes into a player’s “range factor.”

Infielders are also credited for their efficiency in turning double plays, while outfielders can save “arm strength” runs by exhibiting the ability to keep runners from advancing extra bases. Say a ball is hit into the alley between center and left fields. This area of field has been assigned a zone number, and data has been recorded as to how often that hit becomes a single, double, triple, or inside-the-parker. If a center fielder is able to hold runners to a double more often than the league average would suggest, then he is either throwing them out at third, or they aren’t running because they know he has a cannon. Either way, the statistics will show that his arm is saving bases, and thus, runs.

In 2008, when the conservative retards of baseball gave Mclouth the gold glove in center field, he had a -12.5 UZR, estimating that he actually cost his pitchers nearly 13 runs over the course of the season. The conventional stats show that, in center field that year, Mclouth made just one error for a fielding percentage of 99.7%. But he was not so hot in other factors. While his error reduction did save his team an estimated 1.4 runs, his inability to cover ground cost the Pirates about 15 runs. While this range factor won’t show up in fielding percentage, it is obviously an important quality of a center fielder, and now it can be measured.

Jeter’s story is roughly the same. Since 2002 he has cost his team nearly 60 runs due to his inability to cover ground. Like Mclouth, his error reduction is excellent, saving his team about 25 runs over that same span. It doesn’t take a math major to realize the discrepancy here: 35 runs in the hole. Taking all factors into account, Jeter has cost the Yankees about 5 runs a year defensively according to Fangraph’s UZR.

As you check up on how your favorite players are doing defensively, try out Fangraph’s UZR. In the far right two columns there is “UZR” and “UZR/150.” UZR is simply a measure of total runs saved (or lost), and the UZR/150 gives us an idea of what pace he is on.  Positive numbers are good, negative numbers bad. Enjoy 🙂


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: