The Boston Red Sox suffered a tough 3-1 loss to the Philadelphia Phillies on Thursday night, and the decision not to use flamethrowing closer Aroldis Chapman in a critical eighth-inning spot has fans buzzing.

With the game tied 0-0 heading into the eighth, the Red Sox faced a daunting stretch of the Phillies lineup: Trea Turner, Kyle Schwarber, and Bryce Harper. It was the perfect moment for manager Chad Tracy to deploy Chapman, who has been nearly untouchable this season. But instead, Tracy turned to Tyler Samaniego, who promptly allowed his first earned runs of the season—a single to Turner and a massive 417-foot home run to Schwarber—before being pulled with just one out. The Phillies added another run off Zack Kelly, and the Red Sox could only muster one run in the bottom of the inning.

After the game, Tracy explained his reasoning. "With Chappy today, we had talked like, we’re going to use him only in a save situation," Tracy said. "The way we’ve been going offensively, it’s like, ‘Let’s get another zero. How many zeros can we put up to see if we can give ourselves a chance to lead?’ And if you’re down Chappy, the lane for Sammy is there."

The logic? Tracy wanted to save Chapman for the ninth inning, hoping the Red Sox could scratch out a run and give him a save opportunity. But here’s the catch: Chapman pitched the day before, but working back-to-back games is rarely an issue for the hard-throwing lefty. If Chapman had mowed down Turner, Schwarber, and Harper, the Red Sox would have taken a 1-0 lead into the ninth, facing righties Adolis García, Alec Bohm, and Brandon Marsh—a matchup that likely would have favored Chapman.

It’s a classic baseball chess match that didn’t pay off. For Red Sox fans, the sting of this loss is amplified by the feeling that the bullpen’s best weapon was left in the holster when it mattered most. As the team looks to bounce back, the question remains: when do you use your ace, and when do you wait?