Bob Levey - Getty Images
After Bud Norris' excellent start Wednesday against the Phillies, I considered a question about his season. Was Bud affected by Brad Arnsberg's firing?
Certainly, his season started out well before training off some in July. Just taking his first two month splits and comparing them to July and August show a slightly different pitcher, with lowered strikeout rates but similar peripherals.
Was there a reason Bud was getting more strikeouts with Arnsberg, who was fired on June 15? Let's look at the Pitch F/X data for Norris from before and after that date.
Before Arnsberg:
| Type | Count | Selection | Strike | Swing | Whiff | Foul | In Play |
|---|---|---|---|---|---|---|---|
| FF | 723 | 50.6% | 61.0% | 41.8% | 5.5% | 19.4% | 16.9% |
| SL | 564 | 39.5% | 68.1% | 55.1% | 20.7% | 18.8% | 15.6% |
| CH | 141 | 9.9% | 53.9% | 41.1% | 9.2% | 12.8% | 19.1% |
After Arnsberg:
Type Count Selection Strike Swing Whiff Foul In Play
FF
793
49.3%
61.7%
41.5%
5.3%
18.2%
18.0%
SL
599
37.2%
65.4%
53.8%
19.0%
17.0%
17.7%
CH
217
13.5%
62.2%
47.9%
7.4%
20.7%
19.8%
The first thing you'll notice is a pretty even split on number of pitches thrown between the two halves. You'll also notice that there's not much difference between the two charts. Norris throws three pitches and leads with his fastball. His slider is his best pitch and that usage rate remained unchanged wit slightly lower strike rates and swing rates.
The only real, substantial difference is an uptick of about 3.5 percent in the changeup usage rate. This is where the drop in his strikeout rate can be attributed.
See, Norris is getting about 10 percent more strikes with the change than before and saw an increase in his swing percentage on the pitch as well. Since his whiff rate dropped slightly since the beginning of the season, that means more hitters were making contact with the change.
However, they weren't putting the change in play and were instead fouling it off. If you follow the percentage increase in the strike, swing and foul ball percentages, they're all about the same. So, all those extra changes Bud is throwing are getting fouled off, which leads him to use his slider or fastball as an out pitch and may be lowering his strikeout rate.
It seems counter-intuitive that if Norris is throwing his change for more strikes, his strikeout rate will lower, but that's the best explanation I can see from some rather incomplete data. I'll also add the disclaimer about looking at partial season data for pitches. We have a pretty big sampling here, but it's still not a full season's worth of data.
If I had to guess, I'd say this is more about Norris learning how to command the changeup. It could be his best pitch, but he's throwing it where hitters can get to it right now, even if they're just fouling it off. If he can learn to sequence it better and command it more effectively in the strike zone, Norris' strikeout rate could jump again.
0 recs | 10 comments
I’m not seeing anything that strikes me as an “Arnsberg Effect” in those splits. I agree with your conclusion that this probably reflects a continued maturation of Norris and his ability to use the change up.
clack - September 15, 2011
Any chance Bud Norris starts following a Roy Oswalt type model for success
I think its safe to say Norris established himself this year. The biggest difference from this season to last season appears to be the fact that he sacrificed a little velocity for improved control and turned a corner.
I wonder if going forward he will experiment with new pitches. One of the things that I liked about Oswalt was that he always tried to stay one step ahead of his competition by adding pitches to his repertoire as batters would figure him out. I know it takes a special kind of pitcher to add new pitches and be successful with them which Oswalt was, but I wonder if a pitching coach (probably not Brocail) gets a hold of him and adds a new weapon to his selection.
conroestro - September 15, 2011 via mobile
Unrelated but Justice is at it again
http://blog.chron.com/ultimateastros/2011/09/15/astros-are-going-to-lose-100-games-and-that%e2%80%99s-not-close-to-being-the-worst-news/
So Richard continues his bashing of Jim Crane whether right or wrong. What I did find interesting is that Justice expects MLB to take no action and just let the clock expire on Mclane and Cranes deal. Not for sure if he talked to inside sources to come to that opinion, or if he ever talks to any sources for that matter but…… what I also found odd is that Justice lists Kody Hinze on the major league team starting next year. Not for sure if he’s off a year and thinks the Astros will be in the AL West, but he says Carlos will be back probably at first. My guess is Martinez will also be back in left so I’m not for sure where he would stick Hinze.
Also has he forgot all about Brett Wallace.
conroestro - September 15, 2011 via mobile
MLB has already released the schedule for next year; so there is no way that realignment could affect 2012. As I read Justice’s piece, he is just saying that it would be “interesting to see” Hinze get a shot at the big leagues. The lineup he shows with Hinze at first base is prefaced with “it would be interesting…” So, I think he is just saying he would like to see it, not that it will happen.
clack - September 15, 2011
I wonder what his axe to grind against Crane is? He’s a self-proclaimed friend of McLane…is that all there is to it?
CRPerry13 - September 15, 2011
Justice is a friend of Bud Selig. He has gone off on Crane ever since Crane expressed his frustration with MLB’s process. I think somehow Justice thinks that he is indirectly defending Selig.
clack - September 15, 2011
Dick Justice is douche-bag extraordinaire.
StrosSouth - September 15, 2011
Isn’t Crane entitled to defend himself at some point. I for one was impressed at how silent he was for so long with all of the rumors swirling around him.
conroestro - September 15, 2011 via mobile
Another interesting point from the Pitch F/X data….opponents are putting more balls in play against Norris since 6/11. Personally, I think you can look at the quality of the opponents he’s faced since 6/11. Before Arnsberg was fired, the non-division teams he pitched against had a combined Win % of .506. After the Arnsberg firing, his opponents were winning at a .537 clip.
I wonder if the decrease in strikeout rate since then also has to do with facing lineups with patient hitters like the Red Sox, Rays, Phillies, and the Brewers (twice)?
CRPerry13 - September 15, 2011
Actually had really good K numbers vs. Boston and Tampa. 10 in 6 against Boston and 5 in 5 against Tampa. Not quite as good against Milwaukee with 7 in 10.1 and this last Philly game.
MadMartygan - September 16, 2011
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