Best pitcher in baseball? For a long time, that conversation had to include Max Scherzer. But the Nationals ace seemed to recede into the background last season.

For the first time since 2013, Scherzer didn’t finish among the top five in his league’s Cy Young voting. In fact, he didn’t receive a single vote. Scherzer’s 117 ERA+ was his lowest since 2012, his 7.8% walk rate was his highest in a decade and his 1.38 WHIP was a career high. The right-hander's expected ERA, which is based on quality of contact, strikeouts and walks, was 4.36, marking the first time in the Statcast era (since 2015) he had an xERA above 2.81.

At age 36, it wasn’t a stretch to think that he was beginning the decline phase of a career that will likely land him in Cooperstown one day.

But here we are in 2021, and Scherzer has rediscovered his vintage form.

Over his first eight starts this season, he has recorded a 2.10 ERA (184 ERA+) with a 0.76 WHIP, 68 strikeouts and eight walks in 51 1/3 innings. After serving up four homers to the Braves in his first start of the year, Scherzer has allowed only four homers in 45 1/3 innings (0.79 HR/9) over his past seven games. His xERA on the year is 2.61, which ranks in the 89th percentile.

Clubs around the Majors are likely taking notice of his renaissance. Why? Because the Nationals are in last place in the National League East, and Scherzer can become a free agent at the end of the season.

If Washington continues to struggle, Scherzer will be a hot commodity at the Trade Deadline, with the potential to make a postseason impact similar to Justin Verlander’s with the Astros in 2017. Even if he’s not traded, the righty is boosting his free-agent value heading into an offseason that will see a number of big-name starters hit the open market.

Here’s a closer look at how Scherzer, who is scheduled to start Wednesday against the Cubs at Wrigley Field, has managed to turn back the clock in 2021. (All stats are through Monday.)

Improved four-seamer location

While Scherzer is one of this generation’s greatest strikeout artists, he doesn’t rely purely on velocity to overpower hitters. His average four-seam fastball velocity is 93.9 mph this season, close to the MLB average of 93.6 mph.

Yet, his four-seamer has been dominant, limiting hitters to a .156 average and a .325 slugging percentage with 28 strikeouts in 77 at-bats. That marks a significant turnaround from 2020, when opponents hit .264 with a .509 slugging percentage against his four-seamer.

Scherzer’s four-seam fastball whiff rate (misses/swings) is up nearly six percentage points from last year, and only two starting pitchers have posted a higher whiff rate on four-seamers.

Highest four-seam fastball whiff rate, SP, 2021
Min. 100 swings on four-seamers
Jacob deGrom: 36.6%
Lance Lynn: 36.1%
Max Scherzer: 34.3%
Brandon Woodruff: 32.9%
Jameson Taillon: 32.9%

Location has made a massive difference in Scherzer’s improved four-seam fastball performance. Last year, he threw his four-seamer in the middle of the strike zone far too often. More than one-third of his four-seamers landed in the heart of the plate.

As these heatmaps illustrate, the right-hander is doing a better job of elevating his four-seamer and also pitching to the edges of the zone this season.

Elevated four-seamers with high spin rates like the one Scherzer throws aren’t only good for generating whiffs but also forcing batters to get under the ball when they make contact. And he is getting a lot more underneath contact in 2021.

Of the 112 batted balls he’s allowed, 37.5% have been given a classification of “poorly/under,” one of the highest rates in the Majors. (More here on the six batted-ball classifications.) That’s up from 28.5% last season. Hitters have gone 2-for-41 (.049) on under contact against Scherzer in 2021. More than half of those at-bats ended on four-seamers.

His changeup has regained its dominance vs. lefties

Scherzer’s issues vs. left-handed batters last season -- he allowed an .855 OPS vs. LHB (.624 vs. RHB) -- were partially tied to his changeup.

While Scherzer will throw his changeup to righty batters occasionally, he mostly uses the pitch against lefty batters in concert with his four-seamer and cutter.

Left-handed hitters crushed his changeup to the tune of a .362 (17-for-47) average in 2020, but they are down to .087 (2-for-23) in ‘21. It’s a big reason why he has held hitters in these matchups to a .483 OPS this year.

It’s unclear why exactly his changeup was so poor against left-handed batters in 2020. It could have been a small sample size or plain bad luck. Or perhaps it was because his four-seamer location made his changeup easier to pick up. (Maybe all three.)

In any case, it was an outlier. Scherzer’s changeup has long been an effective weapon, and that’s once again the case in 2021.

He’s missing bats with everything

While Scherzer’s bat-missing ability has been elite throughout his career, he’s taken it to another level this season.

His 35.9% whiff rate is a personal best since Statcast started tracking in 2015, topping his previous high of 33.8% in ‘19. He ranks in the 91st percentile after placing in the 81st percentile a year ago.

On pitches in the zone, his whiff rate is also a Statcast-era personal best at 28.8%, tied for the fourth highest among starting pitchers who have generated at least 100 swings on in-zone pitches in 2021.

And Scherzer isn’t just doing this with one or two pitches. He’s doing it with everything he throws. This season, 27 starting pitchers have recorded at least a 30% whiff rate with multiple pitch types (min. 50 swings per pitch type), but only three have done it with at least three different pitch types. Scherzer has done it with four. Even his curveball, which he doesn’t throw as often as his other four pitches, has a whiff rate over 30%.

Most pitch types with 30+% whiff rate, SP, 2021
Min. 50 swings per pitch type
Max Scherzer: 4 (Four-seamer, cutter, changeup, slider)
Gerrit Cole: 3 (Four-seamer, slider, changeup)
Lance McCullers Jr.: 3 (Slider, changeup, knuckle-curve)
24 starting pitchers tied with 2

Scherzer surely won't be going on the trade block anytime soon. The Nationals entered Tuesday trailing the first-place Mets by only four games despite their slow start, and we've seen this club go on a late-season run before, recovering from a 19-31 record through 50 games to win the World Series in 2019.

Still, a bunch of general managers are probably already dreaming of swinging a trade to bring Mad Max to town. The way he's pitching, he could be the ultimate difference-maker this October.