On Sept. 9, a ball hit by Houston's Hunter Pence sent the umpires to the video room. On Tuesday night, a shot hit by Cincinnati's Joey Votto started the process.
In the top of the seventh inning, with the Reds leading, 2-1, Votto hit a drive to right field that appeared to touch the top of the wall before clanking off a first-row seat.
Votto thought he had a home run, but the play was ruled a single by first-base umpire Bill Miller. Votto, Reds first-base coach Billy Hatcher and manager Dusty Baker argued the call.
"It wasn't clear enough to overrule it," Baker said. "They at least gave us the courtesy to try to look at it. That's their first time and my first time with it."
After all four umpires deliberated for several moments, crew chief Gary Darling went to the third-base dugout to review the play. Darling confirmed Miller's call and Votto had to settle for a single.
"There were two looks we had," Darling said. "Neither one gave us clear or convincing evidence of [anything] other than what we had on the field."
The ball has to clear the yellow line to be a home run. Otherwise it's in play.
"It sounded like it [hit above the line]," Votto said. "Apparently there is pole behind the top of the yellow line. They said it hit that."
Astros manager Cecil Cooper thought the ball hit below the line.
"But those things happen so fast and so quick, but obviously they got it right," Cooper said. "It's why we have replay."
Darling was satisfied with how the system worked and that the time was spent looking at the feeds going back and forth.
Since the new rule went into effect on Aug. 28, there have been four instances in which a replay has been used.
All televised MLB games are monitored and staffed by an expert technician and either an umpire supervisor or a former umpire at Major League Baseball Advanced Media headquarters in New York. A television monitor and a secure telephone link to MLB.com, placed next to the monitor, have been installed at all 30 ballparks.
If the crew chief determines that instant-replay review is necessary on a particular disputed home run, he calls the MLB.com technician, who then transmits the most appropriate video footage to the crew chief and the umpire crew on site.
The umpire supervisor or former umpire does not have direct communication with any of the umpires on site, and the decision to reverse a call is at the sole discretion of the crew chief. The standard used by the crew chief when reviewing a play is whether there is clear and convincing evidence that the umpire's decision on the field was incorrect and should be reversed. The use of replay is limited only to home runs: in or out, fair or foul, and fan interference.
"I didn't think it went over. I didn't hear it hit the seats, so I don't think it went over," Astros center fielder Michael Bourn said. "That helped us out, but unfortunately we didn't score another run. I don't have any problem with the replay. It can help us or hurt us, but you want the right call to be made."
Jim Molony is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.