What’s In a Young Pitcher’s Strikeout Decline?

Strikeouts for pitchers aren’t overrated, and here’s why: there is no more fundamental indicator that a pitcher is or isn’t hard to hit. To get strikeouts, you have to throw strikes or pitches that look like strikes, and the batter has to not put those pitches in play. All that’s important for a pitcher to do goes into the generation of strikeouts. There are, of course, relatively ineffective pitchers who get strikeouts. There are relatively effective pitchers who do not get so many strikeouts. Strikeouts aren’t everything, because the name of the game isn’t “Get The Most Strikeouts”, but they are the closest to everything of any of the basic stats. Make people miss and you’re probably good.

So if you want to find pitchers people are buzzing about, follow the strikeouts. If you want to find young potential aces, follow the strikeouts. Yovani Gallardo seemed like a young potential ace. He’s still not old, and he’s still plenty talented. But people have been waiting for him for years. He has yet to post a full-season ERA- under 90. His runs have never quite matched his peripherals. And this past season was something of a worrisome mess. In 2009, Gallardo had baseball’s seventh-highest strikeout rate, essentially equal with Clayton Kershaw. He kept on striking out about a quarter of batters through 2012. This last year, his strikeouts matched Jordan Zimmermann and Edinson Volquez. His rate was still fine, but considerably worse, and it’s enough to make one wonder: what happens when a young starter loses strikeouts?

It would be easier to explain with older starters. They could be hurt, or they could just be reaching the end of the line. Every career dies somewhere, and strikeouts are usually one of the first things to go. We don’t generally expect people to start declining in their 20s, so when you have something like a strikeout decline for a younger starter, is it a blip, or is it an indicator? That is, do pitchers bounce back, or do they just find their new levels?

Gallardo, as it happens, isn’t the only young starter to be coming off a strikeout decline, where “young” is defined as “under 30”. Between 2012-2013, Gallardo’s strikeout rate lost 5.1 percentage points. Stephen Strasburg, David Price, and Dillon Gee each lost 4.1 percentage points. But Strasburg had a big second half, and might’ve been cutting his strikeouts deliberately to get quicker grounders. Price claims to have been working for efficiency, and he countered the strikeout decline by throwing strikes almost exclusively. Gee actually got fewer strikeouts in the second half, so he’s a guy to keep in mind here, too. But Gee already had his shoulder operated on in 2012, and he fought a known elbow issue as well. Gallardo’s never missed time with an arm issue, yet last year his velocity was down across the board. With Gallardo, there was the same workload, but less stuff and fewer whiffs. There’s no apparent easy explanation. In this way Gallardo stands alone.

Let’s go over some history. The first thing we’ll do in the leaderboards is select for starting pitchers. Then we’ll set an innings minimum of 100, and we’ll make sure to only look at guys on the bright side of 30. I took the leaderboards back to 2000, and then I looked for pretty big year-to-year strikeout declines. I somewhat arbitrarily set my dividing line at -4 percentage points. I was left with a pool of 63 pitchers. To repeat all that: there were 63 pitchers

  • as starters
  • since 2000
  • who threw at least 100 innings in consecutive years
  • while younger than 30
  • and had their strikeout rates decline at least four percentage points

Then it was simply a matter of seeing how those pitchers did the next year, the year after losing so many strikeouts. Here’s a table of names and some of the information:

Pitcher Year GS FIP- K% Year X+1 GS FIP- K% Year X+2 GS FIP- K%
2000Bartolo Colon 30 80 26% 34 90 21% 33 86 15%
2001Bartolo Colon 34 90 21% 33 86 15% 34 90 18%
2001CC Sabathia 33 95 22% 33 89 17% 30 90 17%
2001Chan Ho Park 35 93 22% 25 108 18% 7 153 11%
2001Glendon Rusch 33 90 20% 34 110 15% 19 91 16%
2001Javier Vazquez 32 70 23% 34 85 18% 34 74 26%
2001Julian Tavarez 28 97 15% 27 114 9% 0 78 11%
2001Kerry Wood 28 81 29% 33 94 24% 32 85 30%
2001Mike Hampton 32 99 14% 30 112 9% 31 94 13%
2001Paul Wilson 24 104 17% 30 115 13% 28 109 13%
2001Roy Halladay 16 50 23% 34 66 17% 36 70 19%
2001Shawn Chacon 27 101 19% 21 127 13% 23 87 16%
2001Terry Adams 22 75 20% 19 96 15% 0 66 18%
2002Barry Zito 35 91 19% 35 91 15% 34 100 18%
2002Damian Moss 29 115 15% 29 139 10% 2 128 17%
2002Matt Clement 32 81 25% 32 95 20% 30 91 25%
2003Brandon Webb 28 73 23% 35 95 18% 33 78 18%
2003Dontrelle Willis 27 83 21% 32 95 16% 34 72 18%
2003Javier Vazquez 34 74 26% 32 108 18% 33 91 21%
2003Kerry Wood 32 85 30% 22 85 24% 10 113 26%
2003Randy Wolf 33 101 21% 23 101 15% 13 114 18%
2004Ben Sheets 34 59 28% 22 77 22% 17 53 27%
2004Bronson Arroyo 29 83 18% 32 99 11% 35 90 19%
2004Eric Milton 34 119 19% 34 126 14% 26 116 14%
2004Freddy Garcia 31 82 21% 33 91 16% 33 98 15%
2004Gil Meche 23 112 18% 26 123 13% 32 106 19%
2004Jason Marquis 32 106 16% 32 118 12% 33 134 11%
2004Joel Pineiro 21 102 19% 30 107 13% 25 124 10%
2004Oliver Perez 30 77 30% 20 149 21% 22 127 19%
2004Victor Zambrano 25 111 19% 27 105 14% 5 144 16%
2005Josh Beckett 29 79 23% 33 109 18% 30 68 24%
2005Mark Buehrle 33 77 15% 32 112 11% 30 93 14%
2005Noah Lowry 33 91 20% 27 109 12% 26 109 13%
2005Roy Halladay 19 69 20% 32 79 15% 31 81 15%
2006Ben Sheets 17 53 27% 24 93 18% 31 79 20%
2006Daniel Cabrera 26 92 24% 34 112 18% 30 127 12%
2006Jered Weaver 19 87 21% 28 92 17% 30 91 20%
2006Scott Olsen 31 98 22% 33 119 16% 33 115 13%
2006Vicente Padilla 33 91 18% 23 115 13% 29 113 17%
2007Daniel Cabrera 34 112 18% 30 127 12% 9 143 8%
2007Johan Santana 33 88 27% 34 83 21% 25 92 21%
2007Roberto Hernandez 32 91 16% 22 115 11% 24 123 13%
2008Ervin Santana 32 77 24% 23 117 17% 33 107 18%
2008John Lannan 31 111 15% 33 111 10% 25 112 11%
2008Micah Owings 18 104 19% 19 136 12% 0 114 23%
2008Scott Kazmir 27 104 26% 26 101 18% 28 145 14%
2009Brett Anderson 30 87 20% 19 79 16% 13 101 17%
2009Jake Peavy 16 75 27% 17 92 21% 18 80 19%
2009Matt Garza 32 99 22% 32 111 18% 31 74 24%
2009Scott Kazmir 26 101 18% 28 145 14% 1 462 0%
2009Zack Greinke 33 53 27% 33 79 20% 28 76 28%
2010Francisco Liriano 31 64 25% 24 113 19% 28 104 24%
2010Jason Hammel 30 82 18% 27 109 12% 20 77 23%
2010Jered Weaver 34 76 26% 33 83 21% 30 94 19%
2010Jhoulys Chacin 21 77 23% 31 96 18% 14 114 14%
2010Ricky Nolasco 26 95 22% 33 90 17% 31 99 15%
2010Travis Wood 17 84 21% 18 106 16% 26 119 18%
2011Brandon Morrow 30 88 26% 21 86 21% 10 134 17%
2011Chris Volstad 29 111 16% 21 126 12% 0 115 6%
2011Ricky Romero 32 102 19% 32 122 15% 2 206 16%
2011Tommy Hanson 22 97 26% 31 118 21% 13 126 17%
2011Ubaldo Jimenez 32 87 22% 31 127 18% 32 90 25%
2011Zack Greinke 28 76 28% 34 78 23% 28 90 21%

In Year X+2, four pitchers didn’t start a single game in the majors. Six more wound up throwing fewer than 50 innings as starters. Of the remaining 53, 19 had further strikeout-rate declines, while 34 bounced back. Nine exceeded their strikeout rates in Year X.

Let’s play around with those 53, understanding that by doing so we’re already eliminating ten guys from the sample who didn’t do so hot. Some average performance numbers:

YEAR X

  • 29 starts
  • 180 innings
  • 86 ERA-
  • 86 FIP-
  • 22% strikeouts
  • 8% walks

YEAR X+1

  • 29 starts
  • 181 innings
  • 102 ERA-
  • 101 FIP-
  • 17% strikeouts
  • 8% walks

YEAR X+2

  • 27 starts
  • 169 innings
  • 100 ERA-
  • 98 FIP-
  • 18% strikeouts
  • 8% walks

As a group, plenty of these pitchers continued to pitch often, but they didn’t bounce back very much to old levels. After losing about five percentage points of strikeout rate, they gained back just one. So they wound up with sustained losses in both ERA- and FIP-. They went from being good starters to average starters, overall, and there are as many nightmares as success stories.

Credit to Ubaldo Jimenez for bouncing back in 2013. Jason Hammel rebounded in 2012, although he was also newly out of Colorado. Zack Greinke’s strikeout rate shot up between 2010 and 2011. But then, Greinke also lost a ton of ground between 2011 and 2012, and he lost only more ground between 2012 and 2013. Scott Kazmir’s strikeouts plummeted before he disappeared. Daniel Cabrera turned into a catastrophe. Tommy Hanson’s slippage hinted at doom. Brandon Morrow is a total mystery. It’s not the most encouraging group of pitchers, if you’re looking for Gallardo to get back to what he was.

What’s positive is that Gallardo has a long, established track record of getting strikeouts. He’s still not old, he made just about every start a season ago, his stuff still looks more or less like his stuff, and he didn’t have any unusual problems with control. But, he did lose velocity. He did lose strikeouts, with the corresponding increase in contact allowed. Recent history shows that, when a young starting pitcher loses a bunch of strikeouts, more often than not they don’t really come back. Gallardo might have a physical problem, or he might just be declining. But it seems like the probability is that he is what he most recently was. If it’s any consolation, that means Gallardo might no longer be a frustrating ought-to-be ace. That he might just be differently frustrating is whatever the opposite of consolation is.





Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

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pft
11 years ago

What should we make of Tanakas declining K rate in the NPB?

pft
11 years ago
Reply to  Jeff Sullivan

Their K rate was in line with their career averages, and they were in their 30’s when they came over.

Iwakuma k rate did drop off at age 25 but he was injured that same year. His K rate was stable when he went to the Mariners in his 30’s. Kuroda’s K rate increased at 25 before dropping off at age 28 and he was injured the next year, but bounced back the year after. Kurodas k/rate was declining when he came over but that was gradual and looks like age related decline.

Maybe its nothing but I always feel a bit nervous when a 25 yo’s K rate declines.

pft
11 years ago
Reply to  pft

Actually, Tanaka was only 24 last year and 1.8 k/9 off his peak at age 22

AK7007
11 years ago
Reply to  Jeff Sullivan

I’ve also heard anecdotes that there is a philosophical difference between here and Japan – pitchers are taught to basically only throw strikes (a la 2013 David Price), which makes predicting their K-rate here not an exact science. Is there data on Zone% available for NPB?