Let’s Review Some Reader Predictions

Nearly eight months ago, I asked you to predict the future. Here are the words I used to introduce that piece:

In 2017, the fastball rate fell again. It’s been falling for some time now, but in 2017 it fell again, from 56.7% in 2016 to 55.6% last year. There’s some reason to think that the drop in the fastball rate is linked to the increase in baseball’s increasing swinging-strike rate, which in turn is linked to the rise in strikeouts and hit batsmen, and on and on and on. Baseball is a complex system of action and reaction, and small changes can grow large quickly.

So this year, I want to know: what do you think will happen to some of baseball’s key stats, league-wide, in 2018? Maybe you think home-run rates will go up and strikeouts will fall. Maybe you think if home-run rates go up then strikeout rates have to fall. Maybe you think it’s the other way around. I don’t know. But I want to hear from you, and most of all I want to hear why you think certain changes are linked, and others aren’t.

Below are a series of tables featuring 10 years’ worth of data for a few key metrics. I’ve also included percentage changes year over year. Below each table is a poll which asks you to indicate whether you think a given statistic will increase or decrease — and, if so, by how much. Answer each poll, if you wish, and then also indicate in the comments why you voted the way you did on one statistic and not others. In a year or so, I’ll come back to this and we’ll talk about it as a group. Maybe it’ll be interesting. Maybe it won’t! We’ll see.

A lot has happened since I wrote those words: I’ve gotten married, my wife and I moved from Boston to Seattle, and I became a telecommuter (in my day job; this one has always been virtual-only). Oh, and the 2018 season came and went. The future I asked you to predict is now a part of the history books. Let’s see how good you were at reading ahead.

Note: a reader of the March post suggested he/she was unsure if answers should be submitted in percent or percentage point. It’s possible, as a result, that a few ballots could distort the overall results. Because I presented all the original deltas in the form of a percent, however, that is how I have once again presented them here. Fortunately, none of this matters at all!

Fastball Rate

Fastball Rate, 2008-17
Year FB% FB% Delta
2008 60.7% n/a
2009 59.7% -1.65%
2010 58.7% -1.68%
2011 57.8% -1.53%
2012 57.6% -0.35%
2013 57.8% 0.35%
2014 57.7% -0.17%
2015 57.7% 0.00%
2016 56.7% -1.73%
2017 55.6% -1.94%

The bar graph above — and the others like it below — present your expectations of the percentage (again, not percentage point) change you expected for each given statistic between 2017 and 2018. Nearly three in four of you (74.2%, to be precise) looked at the data presented in the table above and decided the fastball rate in 2018 would decline by somewhere between zero and two percent between 2017 and 2018 — about on par with declines between 2015 and 2016 and between 2016 and 2017. And you know what? You were right. The fastball rate in 2018 was 55% even — a decline of 1.1 percent . Good job, everybody. You got this one right. And that pesky fastball rate just keeps dropping.

Walk Rate

Walk Rate, 2008-17
Year BB% BB% Delta
2008 8.7% n/a
2009 8.9% 2.30%
2010 8.5% -4.49%
2011 8.1% -4.71%
2012 8.0% -1.23%
2013 7.9% -1.25%
2014 7.6% -3.80%
2015 7.7% 1.32%
2016 8.2% 6.49%
2017 8.5% 3.66%

There was actually some disagreement about this one. Eight months ago, most of you (58%) thought the walk rate would jump this year — but you weren’t sure how much: 26 percent of you thought it would jump modestly (0%-1%) while 16% thought it would jump somewhat more dramatically (2%-5%). Another 28% of you thought the walk rate would drop, though modestly. And then there were the 14% of you who thought the walk rate would stay unchanged. Those people were right. The walk rate in 2018 was 8.5% — exactly the same as it was in 2017.

Strikeout Rate

Strikeout Rate, 2008-17
Year K% K% Delta
2008 17.5% n/a
2009 18.0% 2.86%
2010 18.5% 2.78%
2011 18.6% 0.54%
2012 19.8% 6.45%
2013 19.9% 0.51%
2014 20.4% 2.51%
2015 20.4% 0.00%
2016 21.1% 3.43%
2017 21.6% 2.37%

This one’s pretty simple. Nearly nine in ten of you (87%) thought the strikeout rate would rise this year, and it did. The 22.3% strikeout rate in 2018 represented a 3.2 percent increase over last year’s all-time record of 21.6% , and there’s no particular reason to think the strikeout journey is going to end any time soon. More strikeouts! More strikeouts! More strikeouts! Congrats to the nearly one in four of you who thought this rate would jump between 2% and 5%. You were right in a very precise way that matters very little to the order of the universe. But, nonetheless, you were right.

Out-of-Zone Swing Rate

O-Swing%, 2008-17
Year O-Swing% O-Swing% Delta
2008 24.9% n/a
2009 25.1% 0.80%
2010 28.7% 14.34%
2011 29.9% 4.18%
2012 30.3% 1.34%
2013 30.4% 0.33%
2014 30.7% 0.99%
2015 30.6% -0.33%
2016 30.3% -0.98%
2017 29.9% -1.32%

This is one of those stats that isn’t especially intuitive or much-discussed, so I’m not surprised that most of you looked at the last six years of data and said, “Yeah, that’s not changing.” Of all respondents, 86% predicted that this stat would vary by less than 1% from 2017’s figure. But here’s the thing: you were wrong. This year’s out-of-zone swing rate of 30.9% represented a 3% increase over last year’s mark and is the highest mark in that category since we started counting in 2002. Go figure. Apparently, 2018 was the year of expanding the zone.

Contact Rate

Contact Rate, 2008-17
Year Contact% Contact% Delta
2008 80.7% n/a
2009 80.5% -0.25%
2010 80.7% 0.25%
2011 80.7% 0.00%
2012 79.6% -1.36%
2013 79.4% -0.25%
2014 79.3% -0.13%
2015 78.8% -0.63%
2016 78.2% -0.76%
2017 77.5% -0.90%

I’m glad you all were consistent, at least. You thought the strikeout rate was going to go up, and you thought the contact rate was going to go down. That makes sense. It’s intuitive. And it’s exactly what happened. Of all respondents, 60% thought the contact rate would decline by between 0% and 1%, and it declined by 0.7% — to 76.9%. You guys should get a hobby.

Home-Run Rate per Fly Ball

Home-Run Rate per Fly Ball, 2008-17
Year HR/FB HR/FB Delta
2008 10.1% n/a
2009 10.1% 0.00%
2010 9.4% -6.93%
2011 9.7% 3.19%
2012 11.3% 16.49%
2013 10.5% -7.08%
2014 9.5% -9.52%
2015 11.4% 20.00%
2016 12.8% 12.28%
2017 13.7% 7.03%

This one was kind of all over the place. Of those who responded, 58% thought this figure would jump in 2018, 33% thought it would drop, and 9% thought it would stay the same. And you had no consistency about how much you thought it would do any of those things. I’m not convinced you didn’t just throw a dart at your computer and pick where it landed (and then throw out your monitor). Anyway, the HR/FB rate was 12.7% this year, which is a 7% decline from last year. Congrats to the 3% of you who got that right.

*****

What have we learned? Well, first, I’m impressed that most of you got most of these right. I guess I shouldn’t be. You all watch a lot of baseball and can read tables reasonably well. You get the crowdsourced contracts generally right, too. I shouldn’t have doubted you.

That’s the first thing. The second thing I’d take away from this is that most of the trends that have made baseball baseball in the last few years — lots of power, lots of strikeouts, and declining contact — stayed the same or accelerated in 2018. Yeah, the home-run rate per fly ball dropped in 2018 — and the number of home runs dropped accordingly — but players still hit a lot of home runs: more by nearly 700, for example, than they hit in 2015, which was itself one of the highest totals of its decade. And we, once again, saw fewer fastballs and more strikeouts this year than we ever have before. So, thanks for reading, and thanks for getting this right. Come back and play again next year. I miss baseball already.





Rian Watt is a contributor to FanGraphs based in Seattle. His work has appeared at Vice, Baseball Prospectus, The Athletic, FiveThirtyEight, and some other places too. By day, he works with communities around the world to end homelessness.

8 Comments
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gregqd
5 years ago

“And we, once again, saw more fastballs and strikeouts this year than we ever have before.” Didn’t the fastball rate go down, and not up?

Yirmiyahu
5 years ago
Reply to  gregqd

I assume that’s a typo, and he meant to say fewer fastballs. There’s also a word missing in the first sentence after the big blockquote at the beginning of the article.