Stealing First

Revisiting the Run Value of Switching a Ball to a Strike

Posted by Dan Turkenkopf - 01/05/08 at 08:05:18 am

Over at Beyond the Box Score, a commenter named Iblemetrician suggested that I reconsider how I calculated the value of switching a ball to a strike.

When I originally calculated the run value of a ball to a strike, I looked at all plate appearances for a given count. That came out to a run value of .161 runs Iblemetrician pointed out that certain counts will have more pitches taken - and even potentially have more pitches on the edge, which might be more likely to be miscalled.

With those suggestions (and after a little bit of programming), I went back and calculated a run value weighting by both called pitches and called pitches on the edges of the strike zone.

Let’s look at the same sort of table as in the first post - this time weighted by called pitches.

B	S	WOBA	LW	RV Ball	RV Strike	RV B->S	Called Pitches	Weighted RV
0	0	0.332	0	-0.0339	0.0426	0.0765	125879	0.0275
0	1	0.283	-0.0426	-0.0269	0.0617	0.0886	43120	0.0109
0	2	0.212	-0.1043	-0.02174	0.2007	0.2224	18148	0.0115
1	0	0.371	0.0339	-0.0626	0.0496	0.1122	41330	0.0132
1	1	0.314	-0.0157	-0.0504	0.0670	0.1174	31151	0.0104
1	2	0.237	-0.0826	-0.0461	0.2224	0.2685	22982	0.0176
2	0	0.443	0.0965	-0.1104	0.0617	0.1722	14736	0.0072
2	1	0.372	0.03478	-0.1026	0.0713	0.1739	14442	0.0072
2	2	0.29	-0.0365	-0.0983	0.2685	0.3667	16318	0.0171
3	0	0.57	0.2070	-0.1170	0.0696	0.1866	7308	0.0039
3	1	0.49	0.1374	-0.1866	0.0757	0.2623	6898	0.0052
3	2	0.403	0.0617	-0.2623	0.3667	0.629	7686	0.0138

Run Value of Switching a Ball to a Strike - Weighted by Called Pitches

Now let’s look at the same breakdown, but considering called pitches on the edge. These are pitches within 2 ball radii of any side of the strike zone (and within the strike zone on the other dimension). That means we’ll count the pitch if it’s one ball width outside the strike zone on the left and middle of the strike zone in height, but we won’t count it if it’s one ball width outside the strike zone on the left and three balls widths outside the zone high.

B	S	WOBA	LW	RV Ball	RV Strike	RV B->S	Called Pitches on the Edges	Weighted RV
0	0	0.332	0	-0.0339	0.0426	0.0765	25248	0.0292
0	1	0.283	-0.0426	-0.0269	0.0617	0.0886	7857	0.0105
0	2	0.212	-0.1043	-0.02174	0.2007	0.2224	2581	0.0087
1	0	0.371	0.0339	-0.0626	0.0496	0.1122	8383	0.0142
1	1	0.314	-0.0157	-0.0504	0.0670	0.1174	5895	0.0105
1	2	0.237	-0.0826	-0.0461	0.2224	0.2685	3533	0.0143
2	0	0.443	0.0965	-0.1104	0.0617	0.1722	2961	0.0077
2	1	0.372	0.03478	-0.1026	0.0713	0.1739	2817	0.0074
2	2	0.29	-0.0365	-0.0983	0.2685	0.3667	2687	0.0149
3	0	0.57	0.2070	-0.1170	0.0696	0.1866	1499	0.0042
3	1	0.49	0.1374	-0.1866	0.0757	0.2623	1376	0.0055
3	2	0.403	0.0617	-0.2623	0.3667	0.629	1318	0.0125

Run Value of Switching a Ball to a Strike - Weighted by Called Pitches on the Edges

I’m a little worried about sample size here - at least comparatively. The results back up the expected behavior though. Players are less likely to take a close pitch with two strikes than otherwise - which lowers the relative run value of those events and therefore the overall run value of “mistakes”.

Update to PITCHf/x Parser

Posted by Dan Turkenkopf - 28/04/08 at 07:04:47 am

I uncovered a bug in the parser script that was causing the nightly update to fail for all dates after the 10th of the month. Grab the new ZIP file for the fix. Also, you’ll need to run the parser manually starting from April 10. If you need any help send a comment or an email.

From the Department of Duh

Posted by Dan Turkenkopf - 27/04/08 at 03:04:23 pm

“The decision to acquire Matt Morris last July did not turn out to be a sound baseball judgment”

-Pittsburgh Pirates team president Frank Coonelly

Really?  I’m sure no one could have seen this happen.  I actually had higher hopes for Morris.  I thought he’d at least be able to hold on through the season.  Or maybe that’s lower hopes for Pirates management.

Why Do Umpires Make the Calls They Do?

Posted by Dan Turkenkopf - 24/04/08 at 08:04:45 pm

My new post summing up the different factors that influence how umpires call pitches is up at Beyond the Box Score.  It’s a continuation and expansion of some of my more recent posts here, so check it out if those interested you.

Stop calling strikes, I wanna go home!

Posted by Dan Turkenkopf - 16/04/08 at 06:04:53 pm

Continuing my look at how different variable affect how umpires call pitches, today let’s talk about what happens in each inning.

We’ll start with a table:

Inning	Runs / 150 Pitches
1	.10
2	.01
3	-.05
4	.03
5	-.03
6	-.08
7	.02
8	-.04
9	.06
10+	-.18

Remember that positive numbers are good for the pitchers (fewer runs), while negatives indicate more scoring.  The innings that jump out are the first, sixth and extras.  I have no idea what to attribute the sixth inning to (perhaps starters are tiring and getting more wild in general - which contributes to umpires being less lenient).  I also don’t really know why umpires help the starters so much in the first - but I’m guessing it has something to do with an unconscious desire to give the pitcher the benefit of the doubt at first, or to start the game off fast.

But I think I understand why the extras (and understand the sample size for all the extra innings combined is about 1/9 of any other inning) are so favorable to the batters.  Without someone scoring, the game can’t end.  If the game doesn’t end, I can’t go home.  I’m sure there’s no conscious reason why the umpires would behave this way, but I’m not sure I’d blame them if there was.  After 3.5 hours of calling pitches, I’d probably want to do everything in my power just to be allowed to sit down.

I’m still working on putting together a longer article combining all this information together.  Unfortunately some of the analysis is taking longer than I was hoping.  Look for it early next week, though.

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