Thursday, March 14, 2013

Bad Announcing: The Perils of Citing Batting Average

So, I'm sitting at home watching the Dominican Republic play the US in a WBC game.

It's 1 - 1 in the 6th inning and Hanley Ramirez is hitting.  Just swung through a Luke Gregerson slider.

This followed a Willie Bloomquist error.

Which followed a Robinson Cano strike out.

Cano was the first hitter that Gregerson faced.  As Gregerson was pitching to Cano, whoever the announcer was made the statement that Gregerson was equally as effective vs righties and lefties and stated that Gregerson had a .216 average against vs righties and a .214 average against vs lefties.  Now, technically, this was true for 2012 but it's totally misleading.

First, Gregerson only faced 117 left-handed hitters in 2012.  117 hitters is hardly a large enough sample to draw meaningful conclusions from.

OBP vs R: .243
OBP vs L: .336

K/BB vs R: 8.40
K/BB vs L: 1.88

In 2012 Gregerson allowed left-handed hitters to reach base 38% more often than right-handed hitters and his K/BB rate was 3.5 times better vs righties than lefties.  Hardly equally effective.

Now the small sample caveats apply here too, of course.  So what's he done in his career?
vs R: .191/.246/.292  with a 3.9 K/BB rate
vs L: .249/.330/.360  with a 2.6 K/BB rate

But, yeah, Batting Average!!!

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