Eight all-time sluggers and eight active stars are set to compete in the ultimate home run competition, and you get to determine who reigns supreme.

The What-If Derby presented by T-Mobile will play out on social media over the next two weeks, with fans deciding who advances from each star-studded showdown.

In the opening round, it will be Ken Griffey Jr. vs. Christian Yelich, Vladimir Guerrero vs. Vladimir Guerrero Jr., Aaron Judge vs. Alex Rodriguez, Giancarlo Stanton vs. Frank Thomas, Mike Trout vs. David Ortiz, Pete Alonso vs. Mark McGwire, Hank Aaron vs. Bryce Harper and Barry Bonds vs. Cody Bellinger.

That’s more than 6,100 combined home runs, 127 All-Star selections and 22 MVP Awards, as well as 12 MLB Home Run Derby titles. But only one of these players can walk away with the crown in the What-If Derby.

Voting for each matchup will get underway tomorrow. Fans can vote on Instagram, Twitter and Facebook, and players will need to win on two of the three platforms to advance.