Ronald Acuña Jr. Is Mr. Baseball For 2023

The Atlanta Braves star founded MLB’s 30/60 club this season, adding prestige to his all-time great combination of power and speed.

With his Atlanta Braves favored to win the World Series, right fielder Ronald Acuña Jr. is making a compelling case to be the National League MVP this season. But whether he wins the award or not pales in comparison with what’s already been accomplished: He’s proven himself to be the game’s greatest offensive threat when it comes to the ever-coveted combination of speed and power.

Acuña secured his place in the record books on Aug. 31. Facing Dodgers pitcher Lance Lynn with the bases loaded, he turned on a 94 mph fastball and launched it into the Los Angeles night at 110.5 mph. The grand slam landed 429 feet away from home plate and made Acuña the only player in MLB history to hit at least 30 homers and steal at least 60 bases in a season — numbers he keeps pushing higher with a month still left in the regular season.

Through Tuesday, Acuña had 32 home runs with 63 steals, putting him on pace to finish with 38 homers and 74 steals. The godfather of sabermetrics, Bill James, long ago created a statistic called the Power/Speed Number, which combines homers and steals. According to this metric, Acuña is on pace for the greatest mix of power and speed in MLB history.

Major League Baseball could have only dreamed of this outcome when it implemented rule changes to encourage more stealing and a more dynamic game this season, all of which Acuña has embraced. A year ago, he swiped 29 bases and hit 15 home runs. This year, he’s been a billboard-sized poster boy for the modern version of the sport.

The only other player who ever came close to founding the 30/60 club was Rickey Henderson, who had a couple of 28/60 seasons in the late 1980s and early ’90s. We’ve seen 40/40 before, most recently by Alfonso Soriano (46 HRs, 41 SBs) in 2006. Acuña himself came close to 40/40 in 2019, hitting 41 homers with 37 steals as a second-year pro. But even if Acuña doesn’t reach 40 homers this season, a 35/75 finish would actually be rarer than 40/40.

Another way of framing Acuña’s unique greatness: The 25-year-old is a new archetype, a player who is more powerful than Henderson and a more prolific base stealer than Alex Rodríguez, the leader in the 40/40 club with 46 steals (and 42 homers) in 1998. 

What makes Acuña such a potent threat? For starters, he’s taking advantage of the new rules, which shouldn’t diminish how we view his output. He’s doing what MLB intended for when it banned infield shifts, introduced larger bases, limited the number of pickoff throws, and created greater urgency for pitchers with the pitch clock.

Stealing bases starts with getting on base — and through Tuesday, Acuña had the highest on-base percentage of his career and in all of the majors this season (.413).

When teams were able to shift defensively last season, Acuña faced shifts 58% of the time (far more than the 20% shift rate for the average righty batter). When the shift was on, his wOBA dropped by 25 points. With shifts now banned, Acuña has a career-best .418 wOBA, including a much higher mark on ground balls in 2023 (.272) than in 2022 (.242).

Last season, Acuña stole 29 bases against 11 times caught stealing — which worked out to a 72.5% success rate, a touch below the league average of 75.4%. This year, Acuña has once again been caught stealing 11 times, but his successful steals have skyrocketed to an MLB-best 63, giving him a vastly improved success rate of 85.1%. 

That’s a remarkable year-over-year jump, even when we consider that the league average is also up to 80.0% this season, with overall steals per game increasing from 0.51 to 0.71. The point is that stolen bases are far more an effective offensive weapon in 2023, and no player has tapped into that change more than Acuña.

Perhaps the most fascinating part of Acuña’s 30/60 emergence is that his raw speed seems to be on the decline. His sprint speed is down from the 97th percentile of all players in 2021 to the 65th percentile this season. And by other speed markers — such as range in the outfield — Acuña is near the bottom of the league. Yet, his ability to read pitchers, get great jumps and pick his spots makes him one of the best base-running threats in today’s game.

The most impressive thing about Acuña’s approach at the plate isn’t that he hit the hardest ball in the majors this season: a 121.2 mph exit-velo homer on Sept. 3 that ranks as the third hardest-hit longball in the Statcast Era. Nor is it the fact that he does that sort of thing consistently, ranking in the 98th percentile of hard-hit rate. It’s that he’s simultaneously in the 97th percentile at avoiding strikeouts — and no other player is in even the 90th percentile of both categories.

We can pinpoint how and where Acuña has improved his ability to punish pitchers: His strike zone chart of weighted on-base average by zone is red-hot pretty much everywhere except high and away, a big change from last season, when pitchers could effectively bust him inside.

None of this is to say that Acuña will or should win the NL MVP award, though he’s worthy of all the consideration he’ll get. 

He was recently passed on the Wins Above Replacement leaderboard by the Los Angeles Dodgers’ Mookie Betts, who has better hitting bona fides (171 OPS+ versus 161 for Acuña) and has been more valuable defensively. Betts has logged at least 15 games in the outfield, at second base, and at shortstop (the first time a qualified player has done so while maintaining an OPS+ of 150 or higher in a season since 1888).

Being the player best suited for modern baseball doesn’t necessarily translate to being a Most Valuable Player. And that’s perfectly fine. Since 1931, there have been 93 MVP awards given out in the National League and 92 given out in the American League (the NL had co-MVPs in 1979).

Throughout the history of baseball, though, there’s only been one Ronald Acuña Jr. And whether he’s in the batter’s box or on the basepaths, his combination of power and speed is likely to give you whiplash.

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Filed under: Baseball