I don’t think you understand. You probably think you understand, but you don’t understand. Oh, you know that Spencer Strider is a bolt of lightning, a strikeout pitcher so overpowering that he might as well have been created in a lab. You know that he’s having a good season, surely; he’s locked in a tight race for NL Cy Young with Zac Gallen and Blake Snell. You know that he’s the logical continuation of the high-strikeout ace lineage, Bob Feller or Sandy Koufax or Roger Clemens for a new age. But I doubt you grasp how much of an outlier Strider’s 2023 season is, because I didn’t either until I took a closer look.
We have pitch-by-pitch data for every major league game on our leaderboards starting in 2002. That means we can calculate swinging strike rate, the percentage of pitches that result in a swing and a miss, for all of those years. I’ll tell you right off the bat that the single-season leader in this category is Jacob deGrom in 2020. In fact, four of the top five seasons on the list are from 2020; they’re outliers that were likely aided by the inherent randomness of a shortened schedule, in other words. For a rate statistic, that makes sense; the fewer innings you can throw to qualify, the easier it is to put up a wild number.
Notice how I said four out of five, though? Strider’s 2023 season is the other one in the group. Batters have come up empty on 19.7% of the pitches Strider has thrown this year. I can’t stress enough how outrageous that is. One way of thinking about it? Here’s a complete list of every non-2020 season where a pitcher recorded a swinging strike rate within three percentage points of Strider’s mark:
Pitchers Within 3% of Strider’s Swinging Strike Rate
That’s it! Gerrit Cole finished the 2019 season 2.9 percentage points shy of Strider’s current pace. By way of comparison, here’s a list of all the seasons within three percentage points of Cole, who was the previous record holder for this particular leaderboard (again excluding 2020):
Pitchers Within 3% of Cole’s Swinging Strike Rate
What a fun trip down memory lane, as well as a reminder that I probably underestimated Matt Clement at the time. But the point is, that list is 67 pitcher-seasons long. The race towards missing more bats was contested, a slow upward climb with tons of contenders for the top spot. Then came Strider, and well, I don’t think we’re going to see a lot of people jostling with him atop the record books any time soon.
I find this hard to fathom. After all, we’ve seen seasons like Strider’s when it comes to strikeout rate. Shane Bieber and deGrom exceeded Strider’s current 38.1% mark in 2020. Cole exceeded it in that superlative 2019 season. Heck, Randy Johnson put up a 37.4% season in 2001. That’s impressive company, no doubt, but Strider isn’t lapping the field like he is in swinging strike rate.
In fact, he stands out in the opposite way here: you might expect him to get more strikeouts given how frequently batters are coming up empty. Here’s a scatterplot of every qualifying season since we have pitch-by-pitch data, excluding 2020:
Strider is that dot out on the far right. It’s not actually that far off of a simple regression line, which would predict a 40.2% strikeout rate instead of his 38.1% number. Cole, meanwhile, is the highest dot; his “predicted” strikeout rate is a mere 34.3%. A one-factor linear regression is obviously far too simplistic – command artists get more called strikes, and so on – but it’s pretty clear that these two skills go together. And it’s just as clear that Strider is great at both.
One underrated aspect of Strider’s season: He’s remarkably consistent. It might feel like he’s a boom or bust type; the Pirates tagged him for six runs in 2.2 innings earlier this month, for example, and he had a handful of other poor performances earlier in the year. But his poor performances aren’t about him failing to miss bats; they’re about everything else going wrong.
The highest swinging strike rate in a single game this year? It’s not Strider; it’s Shane McClanahan, with a whopping 35.2% mark (31 of 88 pitches) against the White Sox in April. Freddy Peralta is second on the list; Trevor Richards is third. Emmett Sheehan and Lance Lynn both have top-10 efforts. One quick note here: I’m using the convention that we use on FanGraphs, which doesn’t count foul tips as swinging strikes. Baseball Savant defaults to counting them, so if you look at their leaderboards, things might be slightly different. But it’s not like Strider’s peak is on a different level than the rest of baseball, however you count.
His consistency, though, my goodness. Strider is fourth on the list – a 29.7% mark on April 24. He’s also sixth on the list – 29.1% on May 12. He’s eighth, 15th, 26th, and 28th, too. That’s six of the top 30 performances this year by swinging strike rate. Peralta has three, and no one else has more than two. Strider has nine of the top 100 games; Peralta and Snell each have four. There’s no one crazy performance driving Strider’s dominance; he’s just doing it nearly every time out.
Here’s another way of putting it: Strider’s worst start from a swinging strike perspective came on June 3. It was a perfectly serviceable start; he struck out seven Diamondbacks over six innings, walked four, and allowed two runs. He threw 99 pitches and garnered 13 swinging strikes, a 13.1% rate. That’s the 1,096th-best swinging strike start (minimum 50 pitches) on the year, out of 4,057 starts (last place: one swinging strike in 97 pitches from Noah Syndergaard on May 31).
That’s Strider at his worst – and it’s more swinging strikes than the major league average. Most pitchers have the occasional clunker in this category. McClanahan has a 6.6% game. Peralta has a 5.9% game. Snell has a 7.8% one. Some days you just don’t have it, or the other guys are seeing the ball well, or any number of other reasons things don’t break your way. There are just so many baseball games. But in every one he’s appeared in this year, Strider takes the mound and guys start swinging.
Is that enough to give him this year’s Cy Young? I have no idea. I’d vote for him right now, but I don’t think his case is overwhelming. But regardless of whether he wins it, what he’s doing is unprecedented. Strider’s 2022 season already felt like a strikeout cheat code – and he had nine different games with a lower swinging strike rate than his worst effort this year. It’s simply hard to wrap your head around how consistent he’s been.
So next time you have a chance — like say, tonight against the Dodgers — check out a Strider start. I can’t guarantee that he’ll shut the other team down, but I can pretty much say for certain that whatever he does, he’ll make a lot of hitters look foolish while doing it. That’s the closest thing you can get to a guarantee in the round-ball, round-bat sport.