Marmol by Month

If you watch Carlos Marmol enough, you realize the importance of his fastball. While his slurve gets the attention, the heater is his key. When Marmol struggles, he actually finds it easier to throw the slurve for a strike, not the fastball. When Marmol can throw the fastball for strikes, he speeds up his opponent's bat and makes the slurve that much more effective.

I've been saying that for a while now. But I've only validated some of those assertions. Questions I have raised:

1. Does Carlos Marmol throw less fastballs when he's pitching poorly?


2. Does fastball accuracy drop more than slurve accuracy when pitching poorly?


3. When the fastball is thrown for strikes, does he get more whiffs on the slurves?

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Let's look at some trends, keeping in mind cause-and-effect are not being addressed.

Month     ERA   K  BB
Apr/Mar  1.56  23   5
May      1.93  31   7
June     7.36  12   9
July     3.97  13  10
August   0.71  14   4

I've mentioned concerns about his high walk rate, even in his post-ASG resurgence, but I see that concern can be put aside at the moment.

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So, there's a pretty clear picture of Marmol's roller coaster ride. How about his pitch mix?

Month     FB   SL   FB:SL
Apr/Mar  147  132  1.11:1
May      141  132  1.07:1
June      93  137  0.68:1
July     101  149  0.68:1
August   115   73  1.58:1

That's pretty much the same roller coaster. So, question #1 is a Yes.

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Let's look at pitch accuracy a few ways.

B:CS  - called pitches
B:S   - all swings are assumed strikes
ISZ   - in zone rate
SwRt  - swing rate

I'm mostly intrigued by swing rates - hitters can probably tell me a lot of what I need to know.

month	year	cfx	B:CS	B:S	ISZ%	SwRt
Mar/Apr	2008	FA	2.0	0.6	0.456	0.463
May	2008	FA	2.5	0.6	0.397	0.461
June	2008	FA	1.8	0.9	0.387	0.258
July	2008	FA	2.9	0.8	0.455	0.406
August	2008	FA	1.4	0.5	0.513	0.435

month	year	cfx	B:CS	B:S	ISZ%	SwRt
Mar/Apr	2008	SL	1.4	0.6	0.477	0.326
May	2008	SL	1.1	0.7	0.417	0.242
June	2008	SL	1.4	0.7	0.438	0.307
July	2008	SL	1.6	0.6	0.456	0.383
August	2008	SL	1.6	0.6	0.452	0.384

Is it just me, or did he struggle a bit with the slurve in May? In any case, it looks like the fastball swing rate follows "the trend" while the slurve also doesn't.





I'll say Yes to #2, his fastball can't find the zone when his slurve still can, especially so when Carlos is performance poorly.

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Last, but not least, does an improved (accurate) fastball help get more misses on the slurve?

 FA ISZ%   SL Whiff Rate
  0.456     0.256
  0.397     0.344
  0.387     0.333
  0.455     0.404
  0.513     0.143

Not so much - perhaps. I'll say No to #3.

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This is rather casual, unsophisticated analysis. Since there's enough validation of my observations, it merits further research. Can we start to find trends in Swing Rate that correspond to impending changes in more traditional performance metrics?

Same thing for pitch selection - if a pitcher (or his catcher/pitching coach) loses "confidence" in a certain pitch, or gains confidence in another, does it indicate a potential shift in his performance?

If someone could recommend a measure of individual game quality - for relievers - I'd be most grateful.