One of the baseball rules changes being tested this year in the independent Atlantic League is moving the pitcher’s mound back by a foot. The idea is to increase offense, and specifically to reduce strikeouts by reducing the ever-increasing velocity of pitches. The mound has been 60 feet, six inches since 1893. We might learn from what happened the last time the mound was moved back.
Until 1892, the pitcher’s box — it was not then a raised mound with a rubber, but a box like the batter’s box — ended 50 feet from home plate. Changing the distance did not move it back a full ten feet, because the rules also changed where the pitcher stood, from having to release the ball by the front of the box to having to stand on the rubber. Still, it was a significant increase in the distance between the pitcher and the plate. This was the last of several changes to the pitching distance, pitching motions, and number of balls and strikes that were made in the 19th century (the count was set at four balls and three strikes only in 1889). The only major change in several decades after that was calling foul balls a strike, which was made uniform across both leagues beginning in 1903.
Part of what happened next is well-known to baseball historians: Offense went off the charts. The National League batted .245 in 1892, the trough of several years of declining hitting; it jumped up to .280 in 1893, with a 39-point jump in the league on-base percentage from .317 to .356. In 1894, the entire league hit .309, an all-time record, and stayed above .290 for three more years. Scoring leaped from 5.10 runs per team per game (many of them unearned runs, in that era before modern gloves and fields) to 6.57 in a single year, and peaked at another all-time record of 7.38 in 1894, and a league ERA of 5.33. In 1894, the Phillies, as a team, hit .350, with four outfielders hitting .400 (Tuck Turner hit .418 and couldn’t crack the everyday lineup). Billy Hamilton scored 198 runs in 132 games. Hugh Duffy hit .440. I could go on all day listing eye-popping offensive numbers. It was a miserable time to be a pitcher.
What is perhaps slightly less well-known is that the pain for pitchers was not evenly distributed. Moving the mound back was practically an extinction-level event for pitchers age 30 and up.
Now, it’s important to understand that the game was different then. Starting pitchers typically entered the league in their teens or early 20s and immediately commenced throwing 400 innings a year, so very few pitchers lasted far past 30. The game also contracted; after a third league was tried in 1890, the second league (the American Association) folded after the 1891 season, leaving National League the last one standing and dropping the total number of franchises from 17 to twelve.
Even so, the results were pretty grim. Using the BaseballReference.com search tools, take a look at the number of pitchers age 30 and up qualifying for the ERA title each year between 1889 and 1899, and their average performance by ERA+ (park-adjusted a measure of a pitcher compared with the league ERA, with 100 being average and above that being better than average):
These pitchers tended, as a group, to be above-average pitchers, men who had lasted in the big leagues for some years. Their number contracted somewhat as the number of rotation jobs declined with fewer teams from 1890 to 1892, but their performance did not fall off. By contrast, the drop-off in 1893 was followed by a further, catastrophic drop in 1894, and it was not until the end of the decade, when the last of the pre-1893 veterans were all gone, that older pitchers recovered to pre-1893 levels. (Cy Young, who was 25 in 1892, turned 30 in 1897.)
Consider some individual cases among pitchers who had been successful past age 30 before the mound moved. While some of them remained effective, they were not the same as before:
- Bill Hutchinson was the most successful over-30 pitcher of the pre-1893 game. Arriving late in the majors at age 29 (Hutchinson had preferred pitching in Iowa, away from the reserve clause that tied players to a single major league club), he was the second-best pitcher in baseball between 1890–92, averaging a 40–27 record, a 2.76 ERA, and 595 innings a year. That massive workload was apt to catch up with Hutchison anyway, but he hit the wall in vivid fashion as a 33-year-old when the mound moved back: 16–24 with a 4.75 ERA in 1893, 14–16 with a 6.03 ERA in 1894. His career was effectively finished after a 13–21, 4.73 ERA season in 1895. By ERA+, Hutchison went from 124 (24 percent better than average) in 1890–92 to just 101 (1 percent better) from 1893–05. By the modern “Wins Above Replacement” (WAR) formula, Hutchison was the only pitcher over the age of 30 to be worth five WAR in the years 1893–95 combined — the other 29 pitchers in that group were all age 29 or under.
- Hall of Famer John Clarkson had 304 career wins through age 30 in 1892. After throwing 620 innings in 1889, Clarkson’s average season from 1890–92 was 28–18 with a 2.84 ERA (ERA+ of 127). In 1893–94, his average season was 12–14 with a 4.44 ERA — still good for an ERA+ of 114, but enough to reduce Clarkson’s workload and convince him to quit the game.
- Hall of Famer Tim Keefe won 342 games in his career and was the all-time strikeout leader when he retired. Keefe was still effective in his thirties with the old distance. In 1888, at age 31, he went 35–12 with a 1.74 ERA. From age 32–35, he had three good years out of four, a natural aging progression. In 1893, however, he fell off sharply from 19–16 with a 2.36 ERA to 10–7 with a 4.40 ERA, walking more batters than he struck out for the first time in his career, although his ERA was still slightly better than league average. Though he needed the money with the country in a depression — Keefe returned to the game in 1894 as an umpire — he never pitched again.
- Tony Mullane won 284 games in his career. A five-time 30-game winner from 1882–87, Mullane’s average season from age 29–33 in 1888–92 was 19–15 with a 2.84 ERA in 306 innings, a 119 ERA+. He was 21–13 with a 2.59 ERA in 1892. In 1893, however, Mullane fell off to 18–22 with a 4.44 ERA (ERA+ of 107), and 7–1 with a ghastly 6.59 ERA in 1894 (ERA+ of 83, so 17 percent below average). Mullane also got blood poisoning from an ingrown nail, so there were some extenuating circumstances.
Veteran pitchers typically have lost some velocity, but can compensate for that by experience — i.e., better command and control of the strike zone, knowing how to locate and change speeds and mix in breaking pitches. Lengthening the mound distance not only makes lost velocity more apparent, it robs pitchers of the benefits of that experience, casting everyone into a new world requiring more adjustments. It is unsurprising that this would land hardest on the veterans. We may not see that directly in the Atlantic League, which has fewer grizzled vets than the majors, but if the big leagues tamper with the distance to home plate, we should expect older pitchers to be disproportionately hard hit.