Of Strikeout Records

Tim Heitman-USA TODAY Sports

In 2001, Randy Johnson had a chance, and not a particularly small one, to surpass the modern-era single season strikeout record. He finished with the third-most in the modern era, at 372, but was held out of his last turn through the rotation to save him for the postseason. This was, of course, the correct decision.

Johnson is the only pitcher to mount a semi-serious challenge to the record since Nolan Ryan set it in 1973. Prior to Ryan's 1973 season, 350 strikeouts had only been topped once, by Koufax in 1965. Since the leagues were still separate, Rube Waddell's American League record of 349 strikeouts had stood since 1904! Ryan would top 350 strikeouts again in 1974.

Prior to the strike in 1994, there had been 23 seasons of 300+ strikeouts, but it was relatively rare, and only once did two players strike out 300 in the same season. Mickey Lolich and Vida Blue struck out 308 and 301, respectively, in 1971.

Since the seventies, the hitting approach and pitching approach have both changed entirely. As a result, despite pitchers pitching less deeply into games, we've seen a surge in the number of pitchers striking out 300. The upper reaches of 300 are probably still unreachable, but just since 2015 five pitchers have surpassed 300, with Gerrit Cole's 326 in 2019 the most strikeouts in any season since 2002.

I've often wondered what Nolan Ryan would do if he was pitching against today's hitters. For reference, as more hitters started to sell out for power at the end of his career, he was able to surpass 300 strikeouts in 1989 at the age of 42, and there were still a number of hitters then trying to avoid striking out. In 1989, just 14.2% of plate appearances in the American League ended in strikeouts, compared to 22% in 2022 (across all leagues, since there is now no difference between leagues.)

In 1973, Ryan struck out 28.2% of the batters he faced, while batters as a whole across the American League struck out just 13.2% of the time. Batters were more than twice as likely to strike out against Nolan Ryan than against another pitcher. To look at it another way, the average team in 1973 struck out 821 times. Four teams in 2022 are within 100 strikeouts of 821 in just half a season. Last season, the Toronto Blue Jays struck out less than any other American League team, and still posted almost 400 strikeouts more than the average team in 1973.

Of course, Ryan wouldn't pitch nearly as many innings in 2022 as he did in 1973, when he hurled 326 innings. However, that might actually work to his benefit. His strikeout rate declined through the game, as would be expected. He'd also be working on four days rest most of the time, instead of the three days of rest he generally had in 1973. Giving him 33 starts with 27 batters faced in a start would be 891 batters faced, which might be a little high. While 43 pitchers have faced more batters than that in the last decade alone, most of them were not big time strikeout pitchers. I feel comfortable assigning Ryan the same number of batters faced as Gerrit Cole's career high of 849. But if he's chasing down a record, he might be allowed a few more batters, so let's make it a round 850.

The increase in strikeout totals has two factors, of course. One is that many more pitchers are throwing hard. Whether or not Ryan really could throw the ball at 108 MPH, he almost certainly didn't sit there. But still, in 1973, it was the threat of the curveball (one of the greatest "drops" ever) that made him unhittable. The problem is how to quantify what percentage of the change results from the batter's approach. The best we can do is provide a range of values.

  • Ryan in 850 batters faced, at same rate as 1973: 240 strikeouts
  • Ryan in 850 batters faced, striking out batters at a clip 13% higher than the league as a whole (this splits the difference between the batters and pitchers): 298 strikeouts
  • Ryan in 850 batters faced, striking out batters at 2.13 times the rate of the league as a whole (the difference in 1973): 398 strikeouts.
So it's certainly possible that 1973 Ryan, pitching under today's circumstances, would challenge the 400 strikeout mark, but he would probably hang out around the 300 strikeout mark with other hurlers of today.

But what about 1989 Ryan, a pitcher with much better control and a third pitch? Helpfully, we also have pitch data for all but one of his starts in 1989, so we can arrive at a much more accurate number of batters he would have faced.

In 1989, Ryan made just 32 starts, and threw between 99 pitches (working into the ninth inning of a win over Cleveland in June) and 164 pitches (8 innings in a loss to the Royals in September.) Obviously no manager is going to let him go over 120 pitches. In 2019, Scherzer topped out at 120 pitches. However, it's pretty simple to narrow things down. 129 times in 1989, Ryan faced a batter for the fourth time. That's not going to happen very often. If we eliminate those plate appearances, we have Ryan facing 859 batters if he was used according to 2022 standards.

1989 Ryan struck out more than 30% of the batters he faced. He actually struck out batters at a higher rate comparable to the AL as a whole than in 1973.
  • 1989 Ryan, striking batters out at the same rate: 262 strikeouts
  • 1989 Ryan, split difference: 309 strikeouts
  • 1989 Ryan, 2.16 times the league rate: 405 strikeouts
Comparing Ryan's 1989 season to the state of the game today, it is actually more likely that he would strike out 400, although still highly improbable. But it is almost certain that he's still striking out well over 300.

But what about Randy Johnson? And what about Sandy Koufax?

Only occasionally did Johnson top 120 pitches in 2001, but it did happen. Applying the same standards to him as to Ryan, he loses 76 plate appearances. But his better control as a whole means that still leaves him with 918 batters faced. The National League as a whole struck out in 18% of plate appearances in 2001, so Johnson does not have the advantage of a huge increase in strikeout rate.
  • 2001 Johnson, striking out batters at the same rate: 344 strikeouts
  • 2001 Johnson, splitting the difference: 367 strikeouts
  • 2001 Johnson, 2.07 times the league rate: 418 strikeouts
In 1965, Sandy Koufax faced almost 1300 batters. He threw 335 innings. He threw 27 complete games. It was a totally different era, and he was a very different pitcher from either Ryan or Johnson. The strikeout rate for the National League in 1965 was 15.66%, well higher than the American League in 1973, largely thanks to the AL adopting the Designated Hitter. Koufax's strikeout rate was only 1.88 times the league average. If we allow Koufax to face 1000 batters, his numbers look good, but only David Price in 2014 has faced so many batters in recent years. 950 seems a more realistic number.
  • 1965 Koufax, striking out batters at the same rate: 280 strikeouts
  • 1965 Koufax, splitting the difference: 361 strikeouts
  • 1965 Koufax, 950 batters faced at 1.88 times the league rate: 393 strikeouts
In conclusion: when people say that 1973 Nolan Ryan wouldn't have struck out 383 batters today, they are likely correct. However, 1989 Nolan Ryan might well have done so, and 2001 Randy Johnson would have had a decent chance to strike out 400.

So why aren't pitchers today challenging the 400 strikeout mark? I suspect that the reason is that a pitcher like Nolan Ryan, Randy Johnson, or Sandy Koufax would never be allowed to develop into a starting pitcher today. All of them struggled early in their careers with control. But they all had great pitches that would have played well from the bullpen. Plus, all of them learned to throw 150+ pitches a game, which requires greater knowledge of pitching than throwing 100 pitches a game. Put any of them in today's game and they are probably still a dominant force. But if any of them were coming up through the player development systems of today, they'd be at best a dominant closer.