Chris Sale is drawing comparisons this season to the most dominant strikeout pitchers in baseball history as he threatens to supplant Pedro Martinez in the Boston Red Sox record book.
Earlier this season, he registered double-digit Ks in eight straight starts, matching a record that he already shared with Martinez. He has a total of 14 double-digit strikeout games this season. That’s just nine off the all-time record and within shouting distance of Martinez’s team record 19 in 1999, according to Baseball-Reference.com. He’s on pace for 324 strikeouts this season, a figure that only Randy Johnson has topped since 1990. If Sale were to end the season with his current strikeout percentage of 36.1 percent, it would be the third-highest in baseball’s expansion era (since 1961). And no pitcher in the American League has ever gotten to 200 strikeouts faster than Sale’s 141⅓ innings, according to the Elias Sports Bureau.
But Sale’s place in history is a curious one. After all, it’s significantly easier to rack up strikeouts when every player in baseball is constantly striking out.
Sale’s numbers seem to be an inevitable byproduct of an era. The strikeout, for pitchers, is still being celebrated, but hitters no longer view the journey back to the dugout after being rung up as a walk of shame. The major league strikeout rate this season of 21.6 percent of plate appearances is the highest ever. And it’s continuing a steady climb: In every year since 2009, the leaguewide strikeout rate has broken a record that was set the previous season. On a player level, this season has 19 of the top 200 pitching seasons since 1961 in terms of strikeout percentage, with Corey Kluber of the Indians (35.8 percent) and Max Scherzer of the Washington Nationals (35.7 percent) joining Sale in the top five.
So how can we tell whether Sale is historically great? A better way to compare baseball’s strikeout kings is to look at how much better each pitcher was than the leaguewide rate.
The strikeout kings relative to era
Pitchers with biggest difference between their strikeout rate and the league rate that season.
| RANK | YEAR | TEAM | PITCHER | LEAGUE K% | PITCHER K% | DIFF. |
|---|---|---|---|---|---|---|
| 1 | 1999 | Red Sox | Pedro Martinez | 16.4% | 37.5% | +21.1 |
| 2 | 2001 | Diamondbacks | Randy Johnson | 17.3 | 37.4 | +20.1 |
| 3 | 2000 | Red Sox | Pedro Martinez | 16.5 | 34.8 | +18.3 |
| 4 | 2000 | Diamondbacks | Randy Johnson | 16.5 | 34.7 | +18.2 |
| 5 | 1995 | Mariners | Randy Johnson | 16.2 | 33.9 | +17.7 |
| 6 | 1984 | Mets | Dwight Gooden | 14.0 | 31.4 | +17.4 |
| 7 | 1999 | Diamondbacks | Randy Johnson | 16.4 | 33.7 | +17.3 |
| 8 | 1997 | Mariners | Randy Johnson | 17.1 | 34.2 | +17.1 |
| 9 | 1998 | Cubs | Kerry Wood | 16.9 | 33.3 | +16.4 |
| 10 | 1989 | Rangers | Nolan Ryan | 14.8 | 30.5 | +15.7 |
| 11 | 1998 | Mariners-Astros | Randy Johnson | 16.9 | 32.4 | +15.5 |
| 12 | 2002 | Diamondbacks | Randy Johnson | 16.8 | 32.3 | +15.5 |
| 13 | 1987 | Astros | Nolan Ryan | 15.5 | 30.9 | +15.4 |
| 14 | 1997 | Expos | Pedro Martinez | 17.1 | 32.2 | +15.1 |
| 15 | 1962 | Dodgers | Sandy Koufax | 14.1 | 29.0 | +14.9 |
| 16 | 1976 | Angels | Nolan Ryan | 12.7 | 27.3 | +14.6 |
| 17 | 1973 | Angels | Nolan Ryan | 13.7 | 28.2 | +14.5 |
| 18 | 1997 | Phillies | Curt Schilling | 17.1 | 31.6 | +14.5 |
| 19 | 1991 | Rangers | Nolan Ryan | 15.2 | 29.7 | +14.5 |
| 20 | 2017 | Red Sox | Chris Sale | 21.6 | 36.1 | +14.5 |
| 21 | 1993 | Mariners | Randy Johnson | 15.1 | 29.5 | +14.4 |
| 22 | 2002 | Diamondbacks | Curt Schilling | 16.8 | 31.1 | +14.3 |
| 23 | 2017 | Indians | Corey Kluber | 21.6 | 35.8 | +14.2 |
| 24 | 1979 | Astros | J.R. Richard | 12.5 | 26.6 | +14.1 |
| 25 | 2017 | Nationals | Max Scherzer | 21.6 | 35.7 | +14.1 |
Let’s take 1999 as an example. When Martinez was striking out 37.5 percent of hitters that season, MLB hitters were whiffing at a rate of 16.4 percent. That difference of 21.1 percentage points is the best since 196115 and dwarfs Sale’s current 14.5 percentage-point improvement on the league average (20th-best since 1961). But this list is top heavy: The margin between Martinez’s 1999 performance and Sale’s current one, for instance, is the same as the gap between Sale and the 129th pitcher-season on the list, Kluber’s 7.9 percentage point difference in 2014.
Johnson and Martinez dominate the top eight spots when you adjust strikeouts for era. The only pitcher who interrupts their run is Dwight Gooden and his 1984 season with the New York Mets. Also ahead of Sale’s current season are several of Nolan Ryan’s and Kerry Wood’s 1998 season with the Chicago Cubs.
Sale’s most impressive accomplishment this season doesn’t even have to do with strikeouts. Even after being uncharacteristically lit up for seven runs on Tuesday against the Indians, his ERA at home is below 3.00 (2.82). That’s no easy feat for a lefty toiling at Fenway, where right-handed pull hitters can smack a glorified pop-up toward the Green Monster and watch it turn into a hit. Only 11 Red Sox lefties have had an ERA under 3.50 in at least 15 starts at Fenway and just one since 1988 (Jon Lester, 2.49, in 2008), according to my analysis at The Wall Street Journal.
In terms of strikeouts, Sale’s season is merely impressive, but perhaps not historic. Meanwhile, Red Sox fans are only left to imagine how many strikeouts Pedro would have in this era of whiff-happy hitters.