Additional Contributors to Rising Strikeouts

Baseball fans, generally, are aware that strikeout rates have been increasing over the period of several years. I wouldn’t say they’re yet “out of control” — it’s not like we’ve got a league of Mark Reynolds against Billy Wagner — but some people have raised some concerns, and, additionally, they’re still trending up. There’s no telling how high the strikeout rate might go. Craig Kimbrel just became the first guy to strike out more than half of the batters he faced in a season. I suspect it won’t be too long before we see another, or at least before we see someone come close.

On Thursday, we discussed evidence that home-plate umpires might be getting better at calling the strike zone. It stands to reason that could be a factor in the rising strikeout rates, since more strikes means fewer balls and you don’t need me to explain this to you, but we covered only the last few years, and also there are presumably a bunch of reasons for the hike we’ve observed. It’s not like it’s all about the umpires, just. Everything in baseball is complicated, and so examining this ought to be complicated.

Now, obviously, there are some clear factors at play. I don’t need to go into depth. Pitchers appear to be throwing harder than ever before. Hitters appear to be more willing to accept striking out than ever before. The former might be due to improved training techniques; the latter might be due to improved baseball analysis. I told you this would be complicated. There’s more, too, and there’s more still pasted below. I hope you’re wearing your table-of-data pants. If not, I hope your current pants are versatile.

Over at Baseball-Reference, I was able to track down pitch data covering the last 25 years, or, since 1988. That seems to be as far back as one can go — whenever I try to access 1987, I get an error. So, I’m satisfied with what we have. What follows is a big giant table, and if you’re curious about the headers, Strike% refers to Strike%. AS/Str% refers to rate of swings at strikes. Contact% is Contact%, 1stStr% is first-pitch-strike rate, 0-2% is the rate of plate appearances that get to an 0-and-2 count, and K% is K%. Sorry for all the numbers.

Year Strike% AS/Str% Contact% 1stStr% 0-2% K%
1988 62% 76% 81% 57% 19% 15%
1989 62% 75% 80% 57% 18% 15%
1990 62% 75% 81% 56% 18% 15%
1991 61% 75% 81% 56% 18% 15%
1992 62% 75% 81% 56% 19% 15%
1993 61% 75% 81% 56% 18% 15%
1994 61% 75% 80% 56% 19% 16%
1995 61% 74% 80% 56% 19% 16%
1996 61% 74% 80% 57% 19% 17%
1997 62% 74% 79% 57% 19% 17%
1998 62% 74% 79% 57% 19% 17%
1999 61% 74% 80% 56% 19% 16%
2000 61% 74% 80% 56% 20% 17%
2001 63% 73% 80% 59% 21% 17%
2002 62% 73% 80% 58% 21% 17%
2003 63% 73% 81% 59% 21% 16%
2004 62% 73% 80% 58% 21% 17%
2005 63% 73% 81% 59% 22% 16%
2006 63% 73% 80% 59% 22% 17%
2007 63% 73% 80% 59% 22% 17%
2008 63% 73% 80% 59% 22% 18%
2009 62% 72% 80% 58% 22% 18%
2010 63% 72% 79% 59% 23% 19%
2011 63% 72% 79% 59% 23% 19%
2012 63% 72% 78% 60% 24% 20%

We can probably go ahead and make this simpler to digest. Here, we break the years into groups of five, instead of proceeding individually.

Group Strike% AS/Str% Contact% 1stStr% 0-2% K%
1988-1992 62% 75% 81% 56% 18% 15%
1993-1997 61% 74% 80% 56% 19% 16%
1998-2002 62% 74% 80% 57% 20% 17%
2003-2007 63% 73% 80% 59% 22% 17%
2008-2012 63% 72% 79% 59% 23% 18%

Feel better? The final column is what we knew about — strikeouts have been going up, rather steadily. If you look at contact rate, there’s a small decline there over the past couple decades. But there’s also a lot more. On average, pitchers have been throwing slightly more strikes. However, hitters have been swinging less often at strikes, meaning there’s been an increased rate of strikes called. More and more plate appearances have started with a strike, and more and more plate appearances have reached an 0-and-2 count.

Obviously, a plate appearance that starts with a strike is more likely to lead to a strikeout than a plate appearance that starts with a ball (or a ball in play!). Obviously, a plate appearance that gets to 0-and-2 is more likely to lead to a strikeout than a plate appearance that doesn’t. Pitchers have generally been able to make hitters miss more often, but they’ve also gotten themselves into more favorable counts, and hitters have been a little more patient. There are those two effects — hitters have been taking more strikes, and when they’ve swung, they’ve missed a bit more.

Strikeouts have been going up, and we don’t know how much higher they might rise down the road. We have a good idea that a lot of this is due to harder throwers and the wisdom of sabermetrics. Everybody knows, now, that strikeouts are good for pitchers. Everybody knows, now, that strikeouts aren’t that bad for hitters. Of course these ideas have been showing up in the gameplay. But there’s more going on than big sluggers just sitting back and swinging hard. It isn’t just more swings and misses, and one should never underestimate the significance of a favorable count. In today’s analytical landscape, counts don’t get enough love.





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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rubesandbabes
9 years ago

This is a cool article and fascinating that the number of 0-2 counts has risen.

The generational move away from seeing batter strikeouts as a bad thing, is to me a result of sabermetrics stats, but citing improved training methods for pitchers is laughable. The scouts have been looking for the strikeout ability since the beginning of time. Sometimes the new stat knowledge doesn’t work any better than ‘don’t draft undersized righties.”

The xFIP stat is basically the strikeout stat, duh..

The problem is the dope, kids. They can’t take the cream and the clear anymore, so what can be taken advantages the pitchers more. It’s just that whole scrotal testosterone patch thing, and now every team has a good bullpen…

Eric Gagne is sorta the poster child here…dopay!

bowie
9 years ago
Reply to  rubesandbabes

what?

Alex Remingtonmember
9 years ago
Reply to  rubesandbabes

I do not believe that scouts have been looking for the strikeout ability since the beginning of time. Look at historical strikeout stats, or even the K/9 of Jim Palmer. Scouts have always liked a good fastball, but especially in the days before the DH and teams having a number of glove-first batters in their lineup, pitching to contact was often a dominant strategy.

Baltar
9 years ago
Reply to  Alex Remington

Wow! A great Jeff Sullivan article and an excellent Alex Remington comment. You’ve made my day.

Rainja182
9 years ago
Reply to  Alex Remington

The 0-2 stat BLEW MY MIND. Seriously, there are brain particles all over my wall right now. What I’m having trouble figuring out is what exactly it means, other than the obvious. Since this has been steadily rising for over 20 years (including the last 5 years) it means that the ‘steroid’ era, and the subsequent ‘clean’ era of the last few years have had cause in this.

It has to be some sort of fundamental change in approach… doesn’t it?

Rainja182
9 years ago
Reply to  Rainja182

Meant to say “of the last few years have had LITTLE cause in this”.