Pitch Type Linear Weights: Our Rotation
Fangraphs just unveiled a new tool from the the amazing minds at www.baseballanalysts.com: Pitch Type Linear Weights. Fangraphs has an excellent introduction to how it’s calculated here if you’re interested, but all you really need to know is that it allows us to look at pitcher’s pitch types and determine which type of pitches get hit around the most, as well as each pitcher's true "out" pitch. Of course, the first thing I did was look at our green and gold.
But first, I needed some sort of frame of reference. The numbers are weighted so that zero is a perfectly average pitch, negative numbers signify below average pitches, and positive numbers are better than average. They also give two numbers per pitch. Using a fastball as an example, wFB is just a counting stat. It's how many runs above average that fastball was over the whole season. Unfortunately, it depends on how many times that pitch was thrown, and for how many innings. What's better for comparison's sake is wFB/C, which extrapolates the performance over 100 pitches. That's the stat I'll be using from here on out. To put things in perspective, Johan Santana's changeup got a 3.01 wCH/C in his 2006 Cy Young-winning season. In other words, for every 100 times Santana threw that changeup, he averaged a hair more than three runs below average saved. That's a very good pitch.
For this analysis, all the stat names are based on a two-letter code for each pitch:
- FB = Fastball
- SL = Slider
- CT = Cutter
- CB = Curveball
- CH = Changeup
- SF = Split-Fingered Fastball
- KN = Knuckleball
To avoid making this Fanpost too long, I'll look at the rotation first.
Dallas Braden - Braden's an interesting case, as this year marks his first year with real consistent success. PitchFX shows him with a fastball, slider, changeup, and new for this year, a cutter. It also shows a curveball, but last year he threw it 0.3% of the time. I'm going to assume these were misclassified sliders.
- wFB/C: -1.49
- wSL/C: 1.44
- wCT/C: 1.35
- wCH/C: 2.66
Immediately, his changeup stands out. That 2.66 wCH/C is pretty great. Additionally, that mark has improved from last year's 1.96, which also isn't exactly bad, by any means. Dallas's fastball isn't doing him any favors, and he throws it 50-60% of the time. Thankfully, his excellent variety of offspeed junk helps him succeed. His improvement in his slider's performance from 2008's 0.35 to this year's 1.44 is worth noting. It also looks like his cutter is a success. Good to see.
Brett Anderson - I'll start with the rookie with more success so far. PitchFX shows a fastball, slider, curveball, and changeup.
- wFB/C: -1.58
- wSL/C: 0.01
- wCB/C: 0.78
- wCH/C: 0.66
Already, it doesn't look as good as Braden. His only above-average pitches so far are his curveball and changeup. His slider is very much average, and his fastball is a hair worse than Braden's. Obviously, as a rookie, it's understandable to not have any dynamite pitches, but on the whole, Anderson's not doing bad at all.
Trevor Cahill - Now we get into the ugly. Cahill throws a fastball, slider, curveball, and changeup, with 0.1% of pitches registering as what PitchFX calls a split-fingered fastball. I'll throw it out.
- wFB/C: -0.96
- wSL/C: -10.53
- wCB/C: -5.33
- wCH/C: 1.07
Yikes. His only above-average pitch is his changeup, and his other three pitches range from bad to atrocious. Take his slider and curveball stats with a grain of salt: he's thrown them 4.1% and 5.0% of the time, respectively, leading to a small sample size, you know the rest. No way his slider will stay ten runs below average. Still, though, it obviously hasn't been the greatest start for Trevor.
Josh Outman - Na na na na na na na na, na na na na na na na na, Out Man! Josh has a fastball, slider, curveball, and changeup.
- wFB/C: -1.19
- wSL/C: 5.35
- wCB/C: -3.41
- wCH/C: 1.84
Look at that slider! That number is probably too high to be sustainable, but still, it's a great pitch. And he's thrown it almost 20% of the time, so this isn't some absurdly small sample size fluke. I don't know what Outman did, but his slider was a full run below average last year. In fact, Josh's best pitch last year, his fastball, was still a half a run below average. That low curveball score isn't as bad as it looks: he's only thrown it 4.2% of the time this year. Additionally, this seems to confirm fears that his speedy fastball is just too straight, without much movement. He's not having very much success with it at all.
Dana Eveland - Not quite the greatest year for Dana. PitchFX shows a fastball, slider, curveball, and changeup.
- wFB/C: -1.12
- wSL/C: -4.83
- wCB/C: -0.61
- wCH/C: 1.30
This is really kind of surprising. The slider, which he throws a quarter of the time, is atrocious. And it was his best pitch last year, at 1.76 wSL/C. Pretty much the only bright spot here is his changeup, which improved over last year by almost two runs per 100 games.
Sean Gallagher - I'm not going to show this year's stats after two games started. You don't want to see them, trust me. Gallagher throws a fastball, slider, curveball, and changeup.
2008
- wFB/C: -0.67
- wSL/C: -0.72
- wCB/C: 0.43
- wCH/C: 0.62
Oh fine.
2009
- wFB/C: -0.47
- wSL/C: 0.83
- wCB/C: -6.78
- wCH/C: -8.50
I'm still going to focus on last year's stats, because of Sean's mechanical issues that he's had this year. Keep in mind that these numbers were the result of 12 games with the Cubs and 11 games with the A's. Gallagher was pretty thoroughly average last year. His fastball and slider were both a tick below average, and his curveball and changeup were a bit above. With Sean's terrible 2009, we can only hope he regains last year's form and adds to it eventually.
Justin Duchscherer - Just for reference I'll look at Justin's amazing 2008 season. To, you know, make everyone else in our rotation look terrible. Or to make us all depressed. One of the two. PitchFX shows Justin with a fastball, slider, cutter, curveball, and changeup.
wFB/C: 0.74
wSL/C: 4.99
wCT/C: 2.45
wCB/C: 1.45
wCH/C: 5.82
Pretty amazing stuff, all across the board. His worst pitch, his 86-mph fastball, was still three-quarters of a run better than average! And that slider and change...wow. There's simply nothing to say except that we need Duke back.
I'll take a look at the bullpen next post. Thanks for reading, guys.
7 recs |
10 comments
Comments
Awesome post!
Great stuff – very interesting.
by Flash G on May 22, 2009 10:30 AM PDT reply actions 0 recs
one thing this stat glosses over
Is that pitchers can’t just get away with only throwing their best pitch. Braden is a great example of this. We all know that his change is his best pitch. I’m sure that Braden knows this too. But he has to keep throwing that below average fastball, or else the change isn’t worth anything. So you basically have to take the full package from each pitcher or else leave it. Any significant tinkering with the frequency of each pitch is probably going to change the run values at the same time.
by colin on May 22, 2009 11:43 AM PDT reply actions 0 recs
Oh, absolutely.
None of this says that Braden should stop throwing his fastball. You’re right in that the changeup’s deception comes from it not being a fastball. But it does show that his fastball is the pitch that gets hit around far more than his other pitches. Basically confirmation that his fastball is not a plus pitch, by any means.
by danmerqury on May 22, 2009 1:20 PM PDT up reply actions 0 recs
Excellent.
You know, when I sat down and decided to write a fanpost, my strategy was just to go to Baseball Prospectus, look at their stat database, and choose one to dissect and discuss. There’s a lot of cool stats out there. I love this work…this is a really nice stat and your analysis is great too. I hope more people do this kind of work.
by ohmangoAs on May 22, 2009 4:32 PM PDT reply actions 0 recs
Thank you.
This is a great piece and I was about to use the new linear weights in the Nico for your eyes only thread, but you do an excellent job here of breaking them down. However when i get done from dinner I have a couple missives about the overall effectiveness of the weighting.
In play, run(s)! Talk dirty to me gamecast, talk dirty. - Nevermoor on FK
by designatedforassignment on May 22, 2009 5:31 PM PDT reply actions 0 recs
This is interesting, thanks -
The hesitation I have with a graph like this is: A pitcher like Braden, for example, throwing a pitch in a fastball count when the hitter is looking fastball – when he throws the fastball it will probably get hit a lot better than when he throws the changeup. But he still has to throw the fastball a lot of the time in order for the changeup to be effective. In fact, what probably determines how much his fastball gets hit is largely how often he’s in hitters counts (2-0, 3-1) vs. how often he can throw his fastball (0-2, 1-2) when they’re not sitting on it.
I’m not suggesting the the data is meaningless, just that I wouldn’t expect its correlation with “quality of that pitch” to be all that high.
I like Cindi. A. She never pretends to know more than she does. B. She has unbridled enthusiasm for her "Hotties," and isn't afraid to show it. -IM4Oakgal
by Nico on May 22, 2009 5:42 PM PDT reply actions 0 recs
When did Duke start throwing a slider?
One thing that’s interesting to note it that is seems your fastball will always get a middling grade, because it’s the pitch you throw the most, and/or because hitters have the easiest time hitting it. Even in the case of Outman, who has an excellent fastball, this is true.
In looking at Duke’s numbers, it’s nice to see how great secondary pitches can make a mediocre fastball look good.
Interesting stuff—thanks for posting.
"PECOTA can pretty much kiss my ass."-Nico
by jeepers on May 23, 2009 8:28 AM PDT reply actions 0 recs
He threw it a lot through 2006 ...
not much since then …
"It's for your own good. Big strong Devo knows whats best for Poppy" -- Mossback
by devo on May 23, 2009 12:49 PM PDT up reply actions 0 recs
Small sample size warnings ahead!
We’ll take Dallas Braden as an example …
Dallas Braden has thrown 875 pitches this season.
I’m assuming you wrote this before his last start, even though it was published after that, because his current numbers are different from those posted. But that’s actually really helpful:
PreGame wSL/C: 1.44
PostGame wSL/C: 0.70
What happened? In the sixth inning, Jason Bartlett deposited an 0-2 slider into the left field bleachers. 875 (the number of pitches he’s thrown) x 14.6% (the percentage of sliders he’s thrown) = 127.75 × .7 / 100 = Dallas Braden’s slider has been worth .9 runs better than average this season (which FG lists, but I thought it would be fun to show some math).
When one single event can change the numbers that drastically, the sample size is much too small. Which isn’t to say the stat doesn’t have value or that this isn’t a nice introduction to it, but rather that we should avoid drawing too many conclusions based on it midseason.
"It's for your own good. Big strong Devo knows whats best for Poppy" -- Mossback
by devo on May 23, 2009 12:48 PM PDT reply actions 0 recs

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