Potential AL SP Strikeout Rate Decliners

A week ago I identified several American League starting pitchers whose SwStk% suggests an imminent strikeout rate surge. I then took a detour to look at both sides of the coin for National League starters, and now I’m back for the potential K/9 decliners in the AL. As a reminder, the league average for American League starting pitchers with a minimum of 120 innings pitched this year is a 7.0 K/9 and 8.5 SwStk%.

Alex Cobb | 7.7 SwStk% | 7.0 K/9

From a skills and SIERA perspective, Cobb has had an excellent season pitching most of the year as part of the Rays rotation. His minor league strikeout rates even give us optimism for better strikeout rates in the future. However, his SwStk% is going to have to improve for him to even repeat the mediocre 7.0 mark he posted this year. He actually posted an identical SwStk% last season, yet only posted a 6.3 K/9, and that’s the downside with such a below average mark.

He does have good control and displayed an intriguing ground ball tendency, so even a drop in strikeout rate won’t kill him. This especially true if his overall luck neutralizes, which would have the effect of offsetting an overall skill set decline and therefore not altering his ERA much. I have been a fan of Cobb and expect him to be a somewhat trendy sleeper next year who could be had very cheaply in some leagues. But, I am not sure exactly what to project for his strikeout rate given the underwhelming SwStk%.

Doug Fister | 8.0 SwStk% | 7.7 K/9

After a breakout 2011 that few people believed in, Fister is proving that his improvement was in fact for real. Combining elite control with a strong ground ball rate, now he has added an above average strikeout rate to the mix as well. The velocity spike he experienced last season has almost completely disappeared, though he’s still up 0.5 miles per hour from 2010. The good news is that his SwStk% is still much higher than it was last year, but has failed to reach even the league average rate. Given his low Z-Swing%, it does appear that he probably gets a lot of called strikes. So I do believe he is likely to continue outperforming his SwStk%, but I think a strikeout rate around 7.0 or slightly lower would be a more realistic projection for next year.

David Price | 8.3% SwStk% | 8.7 K/9

Blasphemy! Raise your hand if you knew that Price’s SwStk% was actually below the league average. It is hard to believe, I agree. His average fastball velocity of 95.5 miles per hour handily leads all qualified starters in baseball, and when you include every starter with at least 10 innings pitched, he still ranks fourth, just 0.4 miles per hour behind fireballer Andrew Cashner. He also mixes in a cutter, curve ball and change-up, yet just once has he posted an above league average SwStk% (and the funny thing is that in that season, his strikeout rate was only 8.1). How could this be? It’s a head scratcher for sure.

Because he put up a nearly identical SwStk% and strikeout rate last season as well, it’s becoming harder to argue for an imminent regression. But all of his plate discipline stats are also very close to the league average so there doesn’t appear to be any hints there. Does he consistently get a ton of foul balls, like way above the league average? If I can’t come up with an explanation supported by the numbers, then he becomes a much riskier proposition than a pitcher whose strikeout rate appears safer.

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Mike Podhorzer produces player projections using his own forecasting system and is the author of the eBook Projecting X: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. His projections helped him win the inaugural 2013 Tout Wars mixed draft league. He also sells beautiful photos through his online gallery, Pod's Pics. Follow Mike on Twitter @MikePodhorzer and contact him via email.

17 Responses to “Potential AL SP Strikeout Rate Decliners”

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  1. JBentley says:

    Mike, I know you tend to do pitching articles (and good ones at that!), but I was wondering if you know of any correlation between batters’ strikeout rate and SwStr%.

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    • I don’t know if any actual study has been published here regarding those metrics, but I have to believe that they are similarly correlated. The higher the SwStk%, the higher the strikeout rate.

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  2. Boof Bonser says:

    Could you point me toward a study that establishes that swinging strike rate is a better predictor of future K rate than past K rate?

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    • There was an article published on either fangraphs or rotographs earlier in the year that included a correlation table between SwStk% and K/9. I can’t seem to find it at the moment. I’m not sure there was anything ever published that compare the predictive abilities of SwStk% vs past K/9 though.

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  3. l1ay says:

    I don’t see why Price should be included.

    I like SwStr % as much as anyone else, but there are always going to be pitchers who have a high K% with a average SwStr % and vice versa.

    I think after nearly 450 IP of an identical K/9 and SwStr % that Price should be included in the aforementioned category.

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  4. Bill says:


    Thinking about next year’s keepers and wanted your input. I have the following pitchers, basically all at the same price:

    Wei-Yin Chen
    Alex Cobb
    Doug Fister
    H. Iwakuma
    Casey Janssen
    Joe Nathan
    Jarrod Parker
    Andy Pettitte
    Chris Tillman

    If I had to keep 6, who would you keep in order of priority?


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    • Really depends on how much closers are worth in your league. Nathan is a top closer and I really like Janssen, though not sure if he’ll be the closer all of next season. I’ll just rank the starters then.




      I assume this is Pettitte’s last year.

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      • Bill says:


        I wonder if you think Fister is now an “ace”, albeit at the bottom of that upper echelon?

        I love the next three too, but I’m surprised that Parker wasn’t separated out somewhat. Of all these guys, who do you think has the highest ceiling? I would’ve said Parker…..

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      • I don’t think Fister’s an ace, not a high enough strikeout rate (projected for next year). Parker’s SIERA is still above 4.00. I’m expecting his strikeout rate to jump, but his ERA makes him appear to be much better than he pitched this year. I think he clearly has the highest long-term ceiling though.

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  5. jim says:

    price and fister get tons of called strikeouts, around 39% each over the past two years have been backwards, compared to just 24% AL average over that time

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  6. Bill says:


    I have a weak observation (with no conclusions),I’d like to throw by you to hear your response. Basically, if a pitcher has a top notch change-up and utilizes it appropriately, they begin to defy strike-out based rules of thumb. Eg: I suspect that is why Parker and hellickson, seem to defy expectations. I wonder if keeping a batter off-balanced is an underrated quality as opposed to hard to square up stuff? Just a crazy idea early in the morning. Thoughts?

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  7. Bill says:

    Perhaps… I haven’t studied it. However, what i have noticed is that certain pitchers are constantly predicted to be likely to regress, with Sierra or k/9 or some other stat weakness sited. Hellickson might be the best example. However, they don’t regress well beyond sample size limits, seemingly. So….. There must be some unexplained reason? I suspect it might be tied to great change- ups? Is this just baseless conjecture?

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    • Papa Tootski says:

      Cole Hamels has a great changeup and the SwStk on it is insane, raising his overall SwStk% quite a bit, so I don’t think it is changeups but rather locating exactly when a pitchers knows he won’t get a swing and miss, throwing junk in a fastball count (i.e. mind games), sinking it for a grounder, cutting it for a pop-up, etc. Park factors and foul ground (think Oakland A’s) can also play a large role.
      For every Strasburg or Kimbrel in the league there is also Buerhle or a Maddux, so xFIP, SIERA, or what have you really don’t apply across the board.

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  8. sboston says:

    I don’t think Cobb got the memo his k rate was due to decline. 3 Innings, 1 hit, 5 k’s. It’s all where you get this cat. If he has a 4.05 era, with 160 k’s, with a whip just south of 1.30, and you’ve spent a few bucks, or drafted way late, you’ve gotten what you paid for. But, if that 68.5% strand rate improves to the year before (74.9), or somewhere in between, there’s growth to be had. Bill James has the K rate at 8.05, he’s on the right team in the right park to pitch… yeah, he prolly will be on lots of sleeper lists.

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