1917-18: Strikeouts on the wane … but why?

Since 1890, these are the largest annual changes in strikeout percentage:

  • 1893, -38%
  • 1901, +32%
  • 1903, +21%
  • 1946, +20%
  • 1918, -17%

And these are the largest annual declines in strikeout percentage since 1890:

  • 1893, -38%
  • 1918, -17%
  • 1899, -10%
  • 1917, -9%

The three largest changes in SO% correspond with major rule changes. In 1893, the pitching distance was increased to 60′ 6″, and strikeouts plummeted. In 1901, the foul-strike rule was adopted by the National League, and the American League followed suit in 1903, with each move bringing a large rise in strikeouts.

The 1946 spike likely has much to do with the postwar return of the regular players — notably Bob Feller, whose 348 Ks in 1946 were one shy of the modern record and accounted for 22% of the raw SO increase over 1945 — and of regular ball-making materials. It still represents an 8% rise compared to 1940, which in turn was the highest rate since 1916. Hal Newhouser, perhaps the most notable holdover from wartime, averaged 5.4 SO/9 in 1944 and 6.1 in ’45, then surged to 8.5 SO/9 in 1946.

But what caused the large drop in SO% in 1917-18?

__________

By 1903 both leagues had adopted the foul-strike rule, and from then through 1916, the MLB strikeout percentage ranged from 9.5% to 10.8%, with no annual change greater than 7%. But in 1917 the rate dipped by 9% — the 4th-biggest drop in modern times — to reach its lowest mark since 1902. A further plunge of 17% in 1918 — the biggest drop outside of the sea change brought by the modern pitching distance — lowered the rate to 7.7%, the lowest since either league counted fouls as strikes. That was 25% below the 1916 rate, and 23% below the 1903-16 average.

Here’s a chart, for you visual types. I’m told that 1917 is purple and 1918 is red:

MLB SO Pct 1904-33

 

The effect was seen broadly:

  • The AL rate fell by 22% from 1916-18, the NL rate by 27%.
  • Out of 97 batters with 200+ PAs in both 1916 and 1918, 70% saw their SO rate fall at least 20% over the two years, while just 3% had a rise of 20% or more. A dip of at least 10% was 11 times as common as a similar increase (80% vs. 7%).
  • Out of 61 pitchers with 50+ IP in both 1916 and 1918, 72% saw their SO rate fall at least 20% over the two years, while just 5% had a rise of 20% or more. A dip of at least 10% was 10 times as common as a similar increase (84% vs. 8%).
  • In 1916, the top 10 marks in SO/9 ranged from 5.9 to 4.7; the 1918 range was 5.2 to 3.6. And note the progression of the 1916 SO/9 leaders; every one declined in 1917 and again in 1918:
Rk 1916 1917 1918
1 Larry Cheney 5.9 4.4 3.7
2 Walter Johnson 5.6 5.2 4.5
3 Allen Russell 5.5 4.7 3.4
4 Lefty Williams* 5.5 3.3 2.6
5 Harry Harper* 5.4 5.0 2.9
6 Tom Hughes 5.4 4.9 n/a
7 Elmer Myers 5.2 3.9 1.6
8 Bullet Joe Bush 4.9 4.7 4.1
9 Claude Hendrix 4.8 3.4 3.3
10 Fred Anderson 4.7 3.8 3.1
11 Dutch Leonard* 4.7 4.4 3.4
12 Al Mamaux 4.7 2.3 n/a
13 Rube Marquard* 4.7 4.5 3.4
14 Babe Ruth* 4.7 3.5 2.2
“n/a” = less than 70 IP
Table provided by Baseball-Reference.com.

But what was the cause? I’ve been searching all day, but I haven’t found it yet.

The size and breadth of the SO drop suggests some change in basic conditions. If the ban on doctored baseballs and the practice of keeping a fresher ball in play could be dated to 1917-18, that alone might explain the decline in strikeouts. But every source I can find dates those changes to the period of 1919-21, and especially to the death of Ray Chapman in August 1920.

The 1918 season was shortened by a month due to World War I, but I can’t see how the lack of September baseball by itself would affect strikeout rates. And while some players did lose time to WWI service or to defense-related jobs, the numbers were nothing like what was to come in the next war.

During 1917-18, there was no change in the official strike zone definition, nor any other significant rule changes to the game on the field.

I can’t rule out changes in visibility at existing stadiums, but no team changed parks from 1916 to ’18.

It’s interesting that the drop in strikeouts was not matched by a significant rise in batting average. The 1916 BA was .2476, rising to .2538 in 1918, a gain of just 2.5%. By comparison, the 1893 drop of 38% in SO% was accompanied by a 14% rise in BA, and the 1899 drop of 10% in SO% came with a 4% rise in BA. It’s also curious that home-run percentage fell by 25% from 1916 to 1918, but slugging average was virtually unchanged.

Whatever the causes, the 1918 strikeout rate became the “new normal.” The MLB SO% stayed between 6.9% and 8.2% from 1918 through 1933.

If you have any ideas on the cause of the 1917-18 drop in strikeouts, let us hear them!

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50 Comments on "1917-18: Strikeouts on the wane … but why?"

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Ed
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Don’t know but the decline was much larger in the NL (3.6 to 2.8; about 22%) than in the AL (3.3 to 2.9; about 12%).

Insert Name Here
Guest

Apparently, there is something called “the Babe Ruth theory” for why the Deadball Era ended (http://en.wikipedia.org/wiki/Dead-ball_era#The_end_of_the_dead-ball_era), which claims that Babe Ruth’s success inspired other players to change their hitting methods, ending the Deadball Era through the increased power numbers brought along by Ruthian hitting. However, the Babe did not become a star as a batter until 1918, so this wouldn’t have affected 1917 strikeout rates, although it could have helped the low rates to become the norm.

Hartvig
Guest
Yeah, but that doesn’t exactly explain why strikeouts went down however. In fact, I know I’ve read quotes from about as far back as I can remember reading about baseball (the early 60’s) of people lamenting high strike out rates and some about Ruth himself- who did manage to lead the league in strikeouts 5 times and finish 2nd another 7- especially in debates about wether Ruth or Ty Cobb was the greatest ever. I have long believed that one of the biggest changes in baseball over time has been a gradual increase in the overall talent level, especially at… Read more »
Insert Name Here
Guest
Re: player quality and worst players: From 1915 to 1916, there was an increase in quality of players due to the folding of the Federal League, which had most of the worst players. The number of players with -1.0 WAR or less decreased by over 70% (down from 27 to 8), although the number of players with negative WAR only decreased by less than 40%. The eight players with -1.0 WAR or less in 1916 were Eddie Mulligan, Lee King, Doug Baird, Zip Collins, Doc Johnston, Jack Tobin (yes, the same Jack Tobin who was a star RF in the… Read more »
William J.
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The strike rates in the Federal League were similar to the NL and AL. Also, the league had folded in 1915, so the impact would have been noticeable in 1916. I do, however, think MLB’s attempt to win back fans may have played a role (see comment below).

Insert Name Here
Guest

Alright, throw out the first two sentences of that paragraph, but don’t throw the baby out with the bathwater; the rest of my comment still seems relevant to me.

However, some sort of league effort(s) to win back fans could have been involved…

Insert Name Here
Guest

Correction: Shorten’s SO% went down *to 5.3%, not “went down 50 5.3%”

Hartvig
Guest

Insert Name Here-

I’m still as confused as I was before as well but that doesn’t mean I don’t appreciate the fine work you did. And ANY mention of Pickles Dillhoefer is a sure way to make certain that today will be just a little bit better than it might otherwise have been.

This is almost as fun a distraction as the Hall of Greats are- my only regret is that they’re not being done sitting around a big table over a few beers.

Well done again, JA

Insert Name Here
Guest

Agreed… “Pickles Dillhoefer” is easily one of my all-time favorite baseball nicknames. “Fritz Mollwitz” (actual first name Frederick, hence “Fritz”) is pretty good too!

Bryan O'Connor
Editor

I was thinking something similar, INH. The graph John presents above destroys the narrative that hitters took pride in making contact and never striking out until Ruth started swinging for the fences and accepting the strikeouts with the home runs, thereby changing most hitters’ approaches.

Mike L
Guest

John A, the US entered WWI in April of 1917. In the beginning, we sent a smaller force “over there” but after the Selected Service act later that year, the armed forces grew to a total of close to 5 million. If you look at the rosters for 1918, there are a significant number of players who played only partial seasons. Here’s a link to WWI players
http://www.baseball-reference.com/bullpen/Category:World_War_I_Veterans

Mike L
Guest

John A (or someone talented), can you graph or otherwise track Ks vs HR’s for 1916, 1917, and 1918?

e pluribus munu
Guest
John, I have no ready suggestions. Your figures took me entirely by surprise – not the 1917-18 ones, but the basic fact that strike outs were so much lower in the early lively ball era than at the height of the dead-ball era (I just went to B-R to check them). I think I’ve always passively believed, as a complement to the theory mentioned by Insert@2, that just as Ruth and the lively ball caused a quantum leap in HRs from 1920, the same was true of K’s (since Ruth’s numbers alone seem to suggest this). Although I knew that… Read more »
MikeD
Guest
I wonder if it is a case of batters adapting but pitchers not? Clean balls, better manufactured balls, banning of spit balls, etc. may have removed an advantage pitchers had built in for years. Couple that with a change if approach of hitters and suddenly hitters had progressed but the pitchers were still clinging to their old style. Yeah, I’m making this up, but just throwing it out for thought. Related, but moving forward to the 1960s, Bill James theorized that the decrease in hitting leading to the year of the pitcher in 1968 started after 1961 when MLB increased… Read more »
Ed
Guest
Just looking at the decline from 1917-1918 this is what I found: 1) Strikeouts were stable throughout 1917 and then dropped off immediately in 1918. 2) The dropoff effected virtually every team. There were a few exceptions (Indians, Red Sox and Browns) but those teams tended to have low K rates to begin with so perhaps they couldn’t get much lower. 3) Every team played in the same ballpark both years and the decline occurred in virtually every park. 4) Most of the umpires were the same in 1917 and 1918 and almost all of them show a pattern of… Read more »
Mike L
Guest

I’m going to throw one more wild-card out there. Rubber shortages during WWI.

Brent
Guest

Equipment related, somehow, due to the War? Something about the baseballs that made it harder to throw hard, or break as much? That is all I can come up with.

I guess twilight comes later in the day in July and August than September (obviously). So maybe not playing games in September made the general lighting better? I am really guessing here.

birtelcom
Editor
Splendid post, John — prompting a new look at baseball of the era. In 1911, 7.16 plate appearances per game ended in a walk or strikeout instead of a batted ball. By 1916, before the precipitous drops in Ks that you identify, that number was already down to 6.66 (perhaps Satan had taken control of the game?). In 1918, it was 5.75, then 5.74 in 1919 and 5.70 in 1920. Although I don’t have much non-statistical evidence for this, I wonder whether a developing understanding that doctored pitches (spit balls, emery balls, etc.) were bad for the game, bad for… Read more »
Ed
Guest
I just skimmed through the 1918 and 1919 Reach Guides. I didn’t see anything mentioned regarding rule changes, playing condition changes, etc. The guide does say that in 1918, 55% if American League players and 64% of National League players were enlisted in the service. So it does seem like there was a fairly large “war effect” at least for that season. Though I’m not sure why that would lead to a decline in strikeout rates. And as John’s graph shows, the lower rates were maintained even after WWI. If anyone is interested in perusing the guides, here’s the link.… Read more »
William J.
Guest

This was an interesting question, so I did a little digging.

The details are in the link below, but the gist is the leagues may have gerrymandered the strike zone a little to help boost offense.

http://www.captainsblog.info/2012/12/28/did-war-on-pitching-in-1917-lead-to-fewer-strikeouts/18724/#more-18724

MikeD
Guest
William, interesting as always. My gut is that the powers that be did “something” to alter the game. Rapid changes in hitting or pitching usually can be attributed to a significant change. An announced rule change, pushing back the pitcher’s mound, introduction of new baseballs. Yet not all changes may be made public, or recorded in the league minutes. This may be one of those cases where the leagues decided to make a change with the goal of increasing interest, but the world was never told. That leads to another interesting question involving Babe Ruth. It’s generally believed his go-for-broke… Read more »
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