The early reviews are in, and they’re very good.

Thursday marked MLB’s Opening Day and the first official use of the pitch clock.

Pitchers have 15 seconds to deliver their throws if no one is on base, 20 if there is a baserunner.

Batters must be in the box and alert to the pitcher with at least eight seconds on the clock.

Player have 30 second between batters to resume play.

The attempt to speed up play seemed to work, with the Yankees and Giants completing their game at Yankee Stadium in a brisk 2:33.

“Gonna cry at how much I love the pitch clock,” former MLB pitcher Brandon McCarthy tweeted. “Truly don’t think people are ready for how much better this will make baseball.

McCarthy, a 13-year veteran who pitched for the Yankees in 2014, was not alone in his praise of the new addition to the game.

“The new pitch clock is incredible,” Ringer founder Bill Simmons tweeted while watching the Red Sox take on the Orioles. “Corey Kluber just threw a 28-pitch first inning in 10 minutes. There was barely enough time to think about how shaky he looked. I love it. Pitch clock! Baseball!”

Bally Sports fantasy guru Brad Evans is on board, as well.

“The pitch clock is one of the greatest devices ever implemented in baseball,” he wrote.

Not everyone will agree, however.

Cubs starter Marcus Stroman entered the history books on Thursday as the first hurler to be called for a pitch clock violation — his third-inning pitch to Brewers slugger Christian Yelich was automatically called a ball.

Giants hitter J.D. Davis took a called strike against Yankees reliever Ron Marinaccio after taking too long to get in the box to being his at-bat.

Red Sox infielder Rafael Devers became the first batter to strike out via pitch clock violation.

Players and managers aren’t the only ones who have to get used to the increased rate of play, as former Deadspin editor Timothy Burke pointed out.

“The pitch clock is WREAKING HAVOC on ballpark organists,” he tweeted.