Pitcher SwStk% Surgers
Yes, it’s still quite early, but I simply cannot help myself from analyzing my favorite advanced pitcher metric — the swinging strike percentage, or SwStk%. The majority of starting pitchers have only started three or four games, but a metric like SwStk% stabilizes relatively quickly, so the typical small sample size caveats don’t necessarily apply to the full degree. The following five pitchers have enjoyed the largest surge in SwStk% as compared to last year. Let’s see if they are doing anything differently, or if it just seems to be a good run.
| Name | K/9 | 2013 SwStr% | 2012 SwStr% | Diff |
|---|---|---|---|---|
| Ryan Dempster | 12.38 | 14.9% | 10.4% | 4.5% |
| Yu Darvish | 12.83 | 15.9% | 11.8% | 4.1% |
| A.J. Burnett | 13.13 | 13.1% | 9.4% | 3.7% |
| Tim Hudson | 6.14 | 10.6% | 7.1% | 3.5% |
| Adam Wainwright | 8.69 | 11.5% | 8.6% | 2.9% |
Ryan Dempster is second among all Major League starters in SwStk%. Over a small sample, this isn’t so surprising though. With the exception of 2003 and 2011, his SwStk% has sat above 10.0 his entire career, which is quite impressive. The only real change in his pitch mix is that he is throwing his splitter about seven percentage points more frequently. Sure enough, that pitch has generated the highest whiff rate this season, and looking at the pitch historically, it always has. So using the pitch more often would seemingly lead to an increased strikeout rate. So far, it looks as if this is exactly the explanation. Of course, since the pitch usually dives down and out of the strike zone, it may increase a pitcher’s walk rate. What do you know — Dempster’s walk rate is up, while his Zone% is way down. If he continues to utilize the splitter at the rate he has, he may very well set a new career high in strikeout rate…but also walk four batters per nine.
We talked a lot about Yu Darvish after his first start, but not so much since. Remember how we were gushing about his velocity surge? Well, that has disappeared. His velocity is now pretty much in line with how he was throwing last season. The difference so far has been that he is throwing his fastball less frequently in favor of his slider. Obviously, a slider is going to generate more swings and misses than a fastball, but it’s thrown for a strike less often. The whiff rate on Darvish’s slider ranks second among his many pitches. Of course, a slider is usually more difficult to control than the fastballBut like Dempster above, if he continues with this shift in pitch mix, his strikeout rate may remain above last year’s, but his walk rate is in danger of rising as well.
36-year-olds aren’t supposed to post career best strikeout rates. But that is exactly what A.J. Burnett is doing so far in this young season. The odd thing is that he’s doing it by using an identical pitch mix to last season. He has increased the usage of his curveball in recent seasons as his fastball velocity has declined, but that has been a gradual shift. Compared to last year, the whiff rates on both his fastball and curve are slightly higher. Without any obvious explanation here when we dig deeper, the likeliest is that he’s just had a good streak and you should expect a strikeout rate closer to last year over the rest of the season.
Clearly, Tim Hudson is drinking the same old veteran water that Burnett is enjoying. The weird thing about Hudson’s SwStk% surge is that it hasn’t yet corresponded to an increased strikeout rate. This year, Hudson has thrown his fastball less frequently in favor of both his splitter and curveball. Those two pitches rank first and third, respectively, in whiff rate. If he continues with this new pitch mix, he might be capable of reaching a 7.0 K/9 for the first time since 2000. Of course, his walk rate may also remain up, while his ground ball rate stays down.
Adam Wainwright has a 28/0 K/BB ratio. That’s not a typo. He has yet to issue a free pass in 29.0 innings. Unfortunately, just like what happened with Darvish, Wainwright’s increased fastball velocity at the beginning of the season was a mirage. That said, he is throwing his cutter much more frequently this season, and surprise, surprise, it has the highest whiff rate of all his pitches. He may be able to maintain a strikeout rate in the high 8.0 range now if he continues to throw the cutter with the same frequency.
Mike Podhorzer is the founder of ProjectingX IQ, an advanced fantasy baseball analytics platform that transforms projection data and in-season performance signals into actionable intelligence. He is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year and three-time Tout Wars champion. He is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. Follow Mike on X@MikePodhorzer and contact him via email.
You the wrong years listed there
Sorry, left out the Have
You have the wrong years listed there
“You keep forgetting to say ‘away’ … yes I know, she’s blowing you guys away. You forgot to say ‘away’ again.” – paraphrased Arrested Development.
I’m thinking “old veteran water” just might be code for something. Can’t quite put my finger on it….
Reading the Dempster comments seems interesting in that a pitcher can utilize a certain pitch more effectively in certain situations. For instance, pitching with two outs and a man on second, would a higher use of the splitter be justified given that a walk does little to the run expectancy, but also increases the likelihood of an out?
I think the likely cause for Burnett is the new C. Their C were just awful last year. Last year he went from the AL to the NL and saw this stat go down even though he was throwing better and my guess would be if you looked into pitch framing you would find the reason.
I got excited when I saw this article because I thought you’d mention my boy, Roberto Hernandez. Dude’s got a SwStr% over 10% and a K rate over 9 right now, plus he’s throwing a changeup over 30% of the time, the highest rate of his career. I’m getting into a dangerous area as I’ve now mentioned him in the comments of 2 or 3 different articles, but I’m just tickled by a guy who gave himself the fake name “Fausto” and might now be reinventing himself at the age of 31.
There’s no test for selling your soul to Satan. Figure that one out, Selig.
What about Jose Quintana, looks like an all around improvement so far. Pitches moves more, fastball is faster, better SwStk%, more strikes in general. Could be a useful #3 pitcher in deeper leagues.
Yeah, would love to see the same article but for deep leagues, focusing on guys like Quintana and the artist formerly known as Fausto. Guess it’s tougher to know whether they’re for real yet, but maybe in a few weeks.
Being in a deeper league (28 teams in my case) makes you care for all kind of players. I just traded Pete Kozma and Conor Gillaspie on back to back weeks.
I think dempsters first pitch strikes and league change also supports the above…someone is trying to sell me on him and I night bite soon
I generally love these SwStr% articles, but other than Darvish the sample size we have on these old guys is so large compared to the sample size of this season it doesn’t move the needle much for me.
Apparently, Darvish is seeing another velocity surge today (4/24), consistently throwing his fastball at 95-96 mph while hitting 97 and 98 mph as well on a few occasions. I think the velocity increase could actually be considered as legitimate because he showed increased velocity in his first start this season, but at the end of which he injured his hand with a blister. These blisters may have affected his performance throughout the next two or three starts, even incrementally, as his velocity has again shown improvement in his last two starts when he has gotten healthier and the blisters have healed.
Another scenario could be that Darvish has the potential to throw at 95mph plus any game, but doesn’t need to rely on fastball velocity as much in some games due to either his lack of feel or command for this pitch, or the fact that he feels that another pitch or pitches may be working for him on a certain night and he feels more comfortable throwing more of this pitch(es) instead of relying on the fastball as much, and thus deducting some effort in trying to throw his fastball at higher velocities because perhaps he feels he can garner the same or better results using whatever other pitch or pitches he has working for him that night. Since Yu has so many different fastballs, the pitch f/x tracking systems probably classify a couple different fastball types together when calculating his average velocity numbers. This may not seem like it may matter that much on the averages, but Yu may not even throw his max velocity (4seam or whatever) fastball in every outing, perhaps instead using cutters, sinkers, 2seamers, or some mix thereof. Since the overall movement and locations of some of these fastball types are bound to look similar when just looking at the pitch f/x data, and so the fact remains that some different pitch types could be getting classified together under the broad category of fastball and thus bring down the average velocity numbers. Perhaps all of this has no effect, but it just seems like a plausible explanation for deviations in his fastball velocities from start to start.
Update:
To further enhance my point, I was just looking at the pitch by pitch data for Darvish’s outing on 4/24 vs the Angels and in the 6th inning while Darvish was pitching to Hamilton, one 95mph pitch was classified as a 4seam fastball, a 96mph pitch later in the same at bat was classified as a 2seam fastball, and a 91mph pitch in the same at bat was also called a 4seamer, meanwhile a 93mph pitch against Borjous in the same inning was classified as a cutter. Similar examples of pitches at the same velocities of 95 or 96mph getting classified sometimes as 2seamers and sometimes as 4seam fastballs exist throughout the pitch summary of this game. So it seams plausible that some of his pitches are getting classified incorrectly or at the very least, not classified consistently from pitch to pitch (making it possible that high velocity sliders or cutters in the high 80s/low 90s perhaps getting classified together with a 96mph 4seamer under the general fastball category, and thus bringing down his velocity averages in certain games)