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.
Fastball Rate
Fastball Rate, 2008-2017
| 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% |
Walk Rate
Walk Rate, 2008-2017
| 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% |
Strikeout Rate
Strikeout Rate, 2008-2017
| 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% |
Out-of-Zone Swing Rate
O-Swing%, 2008-2017
| 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% |
Contact Rate
Contact Rate, 2008-2017
| 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% |
Home-Run Rate per Fly Ball
Home-Run Rate per Fly Ball, 2008-2017
| 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% |
I’m guessing contact rates are up related to speed of play changes- or maybe I’m just hoping.
I basically tried to eyeball regression for most of these, but I do think HR/FB will go up decently (I said 1-2%) as everyone buys into the fly ball revolution and guys with higher HR/FB rates get more looks. Seems people agree with me on this.
I have a gut feeling that the ball is going to come back to Earth. In the past, HR outlier seasons generally regress.
At some point we will look back and be able to recognize peak juiced balls – much like the steroid era. That may have been 2017 as it seems to have gotten MLB’s attention at least, I don’t claim to know anything that everyone else doesn’t about that. Maybe it is a year or two away, but I don’t think this flyball revolution sticks without juiced baseballs. It might stick to some extent, but I don’t think it is the revolution that most people do. That will be a fun trend to monitor over the long term – for me at least. A year ago, this community was committed to the idea that balls were not juiced, which is crazy to think. It is weird to see that the flyball revolution has stuck, but the elephant in the room doesn’t get pointed at. As long as balls fly, I think we will see more flyballs, but when the balls come back I think guys will have to adjust back.
On the other hand, if pitching keeps getting better, with better velocity and control, it may remain the best strategy to try to hit home runs at all costs. If the old “string together a few hits” is just not likely to work out, why not swing for the fences in case you hit it?
Everybody is buying into the Launch Angle and trying to increase their Exit Velocity – that’s why the Home-Run Rate per Fly Ball will probably increase. How much? It could increase more than 10%, like it did in 15′ and 16′, but more likely (based on the trend from the 20% peak in 15′) it’ll be somewhere between 5-10%, and it wouldn’t be a shocker if it’s <5% because many players were already trying to use the LAwEV physics last season.
Exit velo is not launch angle. They are different things. You can hit a ball with elite exit velo into the ground.
Some people are trying to affect the pace of play when should be worried about the amount of action. I think one of the biggest drawbacks of the combination of more strikeouts and more home runs is fewer high leverage situations. 2017 had fewer high leverage situations than any other year since 2000 and it was not close.
This “amount of tension” is my concern.
Home runs are exciting when they happen, but nothing when they don’t, which is a lot more often. Bases loaded singles and bases loaded groundouts are both exciting to different sides.
What caused that O-Swing% spike in 2010?
He’s using BIS plate discipline so my guess is it’s just them adjusting what they consider to be in/out of zone pitches. They probably started to use pitch f/x data that year. League average zone rate went from 48% to 45% from 2009 to 2010.
I think declining fastball rates are an artifact of the philosophical shift from “baseball by the seat of your pants” to “data driven”. How many old school pitching coaches swore that the fastball is life? That you can’t pitch in the MLB without starting with your fastball? Recently, the data is saying “yo some of these guys have some *really good* non fastballs, they should throw that more”, and it’s working. So there’s a much wider repertoire in the bigs now, I think. That also means that the FB% should stabilize “soon”, say within the next decade or so, as the shift in thinking (and coaching turnover) completes.
The way you worded these polls makes it EXTREMELY hard to tell whether you’re asking about percentage-point changes or percentage changes. I finally figured out (I think) that you mean the former, but it’s probably going to bias the result that some of your audience doesn’t scratch their head over it quite as long as I did mine.
My guess is also that Hr rate regresses. i see a landscape trending younger, so i see more fastballs, more ks but the charts showed me that incremental is the most likely result