Even More First Pitch Swinging – Starters vs Relievers

In the comments to the first first pitch swinging post Nate asked about the differences in the time of game reasoning that the value in wearing down a reliever is minimal. It was easy enough to break it down by starter versus reliever.

The Tigers swung at the first pitch slightly more against relievers going after 32.6% of first pitches as opposed to 30.7% for starters.

Below are the results from those swings:

					BA	OBP	SLG	Ball	Strike	In Play
					----	----	----	----	----	----
Starter - 1st pitch - Take - Full AB	.274	.339	.441	1591	1192	
Starter - 1st pitch -Swing - Full AB	.316	.330	.542		718	524
Starter - 1st pitch -Swing - In Play	.400	.393	.652			524
Reliever - 1st pitch -Take - Full AB	.244	.331	.384	847	559	
Reliever - 1st pitch -Swing - Full AB	.271	.294	.452		433	254
Reliever - 1st pitch -Swing - In Play	.348	.345	.530			433

The Tigers fared much better against the starters. So much for that theory of getting to the weak part of the bullpen.

One area of disparity was the in-play rate of the first pitch. Against the starters the batters put the ball in play 42% of the time versus 37% against the relievers meaning that they found themselves down in the count more often against the pen. However, starters were more effective at getting that first called strike getting ahead on the takers 43% of the time against 40% for the relievers.

Make of this what you will.


One of the things that would make all this more useful is some context. While I could examine all of baseball, or at least all of the American League I don’t see that happening. I run into some technical limitations in that I’m capped by Excel’s row count. The number of events simply blows out the max number of rows. While I could do this in a database (and a chunk of the work I do in Access), I’m much more nimble in Excel.

Fortunately, today I came across some work that was already done by Larry Borowsky of Viva el Birdos. He took a look at National League first pitch data from 2004 and found some similar trends -but with varying magnitudes. One element that you may find interesting is the median team first pitch strike rate was 48% in that sample. The 2006 Tigers checked in at 47.5%.

Larry came to this conclusion which I can’t help but agree with:

On the contrary, from this study — admittedly limited, one league one year — it appears that aggression is an essential component of discipline. You have to keep the pitchers honest, take the get-me-over fastball out of their kit and force them to work the corners from the beginning of the at-bat. That’s how you get favorable counts — make the pitchers work fine on 0-0, take part of the plate away from ’em. So it’s not all about running deep counts and waiting for your pitch; it’s about knowing the strike zone and recognizing your pitch — even if it happens to come on 0-0.

The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at www.retrosheet.org.

For the sake of completeness, here are the links to the other 2 articles done here: First Pitch Swinging and More on First Pitch Swinging – Runners on Base

4 thoughts on “Even More First Pitch Swinging – Starters vs Relievers”

  1. To follow on my post on your last “first pitch” column, I agree with your and Larry’s opinion: the key is getting a good pitch, regardless of count. The issue with some of the Tiger hitters is not swinging at the first pitch, it’s swinging at a BAD pitch that happens to be first.

  2. Thanks for taking a look at those splits. I guess my resoning wasnt as solid as I thought it would be. It ceratinly looks like most relivers deserve more credit than I give them.

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