The race to 40-40 is on, and two top contenders are about to go head to head.

There have been only four 40-homer, 40-steal seasons in AL/NL history, but with MLB’s 2023 rules changes leading to an increase in stolen-base attempts and success rate, the chances of the 40-40 club gaining a new member are better than they’ve been in years.

Two of the top preseason candidates to accomplish the rare feat -- Atlanta’s Ronald Acuña Jr. and Houston’s Kyle Tucker -- will share the field Friday night when the Braves host the Astros in a showdown between the last two World Series champions (and a 2021 Fall Classic rematch) on Apple TV+ at 7:20 p.m. ET.

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Here is a look at these two dynamic power-speed threats, the history they’re chasing and what it will take to get there.

Acuña back in superstar form

Acuña produced 41 homers and 37 stolen bases over 156 games in 2019, the closest run at 40-40 since Matt Kemp came up just one big fly short in 2011. (Even so, at age 21, Acuña became the youngest 35-35 player in history). He also had an outside shot at joining the club two years later, as he had 24 homers and 17 steals through 82 games before suffering a torn ACL in July 2021.

The injury caused him to miss Atlanta’s run to a World Series title, culminating with a win over the Astros in six games.

After returning to post a career-low .764 OPS with 15 homers and 29 steals over 119 games last year, Acuña appears to be back to full strength. The 25-year-old is slashing .367/.451/.544 with three homers and eight stolen bases for a Braves juggernaut that has gone 14-5, winning eight straight games before dropping its series finale at San Diego on Wednesday.

Acuña’s production through 19 team games puts him on pace for a 25-homer, 68-steal campaign, the likes of which haven’t been seen since Rickey Henderson went 28-65 on his way to 1990 AL MVP honors. Even with his 88th-percentile sprint speed, Acuña may not continue to run at quite that clip, but on the other hand, his homer output could increase. Summer weather should help, as would trimming down a career-high ground-ball rate (53.8%) that is so far blunting the impact of Acuña’s prodigious power.

Don’t sleep on Tucker

Acuña is probably the first name that comes to mind when you think of potential 40-40 players among the current crop of MLB stars, along with other multidimensional players such as the Mariners’ Julio Rodríguez, the Guardians’ José Ramírez and the D-backs’ Corbin Carroll.

But underestimate the quietly potent Tucker at your own risk.

The 26-year-old ranked below the 40th percentile in sprint sprint last year and is doing so again in 2023, putting him on par with hulking Blue Jays slugger Vladimir Guerrero Jr. And yet, he swiped 25 bases in 2022, by far the most among the 23 players who hit at least 30 homers. He’s already 4-for-4 this year and now 57-for-65 in his career, with his 87.7% success rate trailing only Byron Buxton among active players with at least 50 attempts.

Volume of attempts is likely the biggest challenge for Tucker, although his increased patience (18.5% walk rate, .438 OBP) could lead to more running opportunities. For now, he has a .984 OPS to go with four homers and four steals, putting him on a 34-34 pace in the early going.

Coming off a World Series title in 2022, the 9-10 Astros are still searching for consistency this season. Their lineup has been missing Jose Altuve and Michael Brantley due to injury, while Alex Bregman (.665 OPS) and new acquisition José Abreu (.605) have struggled to get things going. But the steady Tucker, along with Yordan Alvarez, is carrying the torch.

The chase for 40-40

Acuña and Tucker aren’t the only challengers, of course. Sixteen other players had at least three homers and three steals entering Thursday, including Rodríguez (4-4), Carroll (4-7) and Tucker’s teammate Jeremy Peña (3-5). So what would it take for any of them to reach the promised land? 

As the Braves and Astros get set to play their 20th games on Friday, here are some targets to keep in mind through the first half of the season, with the past 40-40 men as context.

Through 20 games
To be "on pace" -- 5 HR, 5 SB
Alfonso Soriano (2006) -- 7 HR, 5 SB
Alex Rodriguez (1998) -- 8 HR, 2 SB
Barry Bonds (1996) -- 6 HR, 4 SB
Jose Canseco (1988) -- 7 HR, 8 SB

Through 50 games
To be “on pace” -- 13 HR, 13 SB
Alfonso Soriano (2006) -- 17 HR, 12 SB
Alex Rodriguez (1998) -- 19 HR, 7 SB
Barry Bonds (1996) -- 17 HR, 12 SB
Jose Canseco (1988) -- 12 HR, 17 SB

Through 81 games
To be “on pace” -- 20 HR, 20 SB
Alfonso Soriano (2006) -- 24 HR, 18 SB
Alex Rodriguez (1998) -- 27 HR, 22 SB
Barry Bonds (1996) -- 23 HR, 20 SB
Jose Canseco (1988) -- 23 HR, 22 SB

It goes without saying that health is essential here. Each of the four previous 40-40 seasons included at least 158 games played, with little margin for error.

When they reached 40-40
Alfonso Soriano (2006) -- 147th game (148th team game)
Alex Rodriguez (1998) -- 153rd game (153rd team game)
Barry Bonds (1996) -- 158th game (160th team game)
Jose Canseco (1988) -- 151st game (154th team game)

Even with stolen bases up across baseball, 40-40 will be a steep uphill climb for anyone. But Acuña and Tucker look like two of the strongest hopefuls in the early going, and on Friday, they will both have a chance to take a step in the right direction -- on the same field.