"This is going to be a critical part of the game," Bochy said of the new layer of strategy.
But the Giants' first defeat of the season was rooted in more than just the replay rule's novelty.
They rocked D-backs starter Wade Miley with four first-inning runs, three coming on Brandon Belt's second homer in two games. But Miley retired the next 15 Giants he faced after Belt's long ball, and 19 of 22 until he departed following the seventh inning. San Francisco mustered three hits over the final eight innings.
The Giants had every right to feel good about their instant offense. They hadn't lost a game in which they scored four runs in the top of the first inning since Sept. 22, 2006, at Milwaukee.
"These guys are good," Arizona manager Kirk Gibson said. "If you don't get the ball where you're supposed to get it, they're going to pound you."
But Miley found his location before the Giants could overwhelm him.
"He got in a groove and we couldn't do anything," Bochy said.
Referring to the repeated complaints the Giants directed toward home-plate umpire Eric Cooper, Bochy added, "[Miley] threw some inside pitches that our hitters were frustrated by. But what could you do? He settled down and got deep into the game, which is a credit to him after giving up four in the first."
Cain stumbled from the starting gate, yielding a pair of first-inning runs that partially offset the Giants' outburst in the top of the inning. He lasted five innings, surrendering three runs (two earned) on seven hits.
Cain, who allowed five hits to the first eight batters he faced, acknowledged lacking command of his pitches. But he righted himself enough to blank Arizona in the second and third innings. Then he tried to pick off Pollock from first base with two outs in the fourth inning, leading to Bochy's rebuffed challenge. The call was upheld, meaning there was not enough evidence to overturn the call.
Gerardo Parra's double advanced Pollock to third. Catcher Buster Posey then was crossed up by a Cain pitch and the ball scooted away. However, Posey quickly gathered the ball and flipped it to Cain, who was covering home plate. A sliding Pollock tried to score and it appeared that Cain tagged his foot before it brushed the plate.
But Cooper called Pollock safe, and since Bochy was out of challenges he could not ask for a review. And because it was before the seventh inning, neither could the crew chief, according to the rules.
"He was out," Cain said matter-of-factly. "I had him. I saw what Cooper saw. It looked like [Pollock] went over the plate through the top of my glove. But it was a bang-bang play. Pollock did a good job of trying to avoid the tag."
Said Pollock, "That was just a weird play. Buster got crossed up by a heater or a cutter or something. It was just really weird seeing that and I thought it was going to kick all the way to the backstop. It was kind of one of those where he flipped his glove a little bit and deadened the ball a little more than I expected.
"Everyone is saying I was out, I kind of did a kick stop and hop over the glove there and I kept looking at the replay. I didn't feel a tag and I kept looking. It was a pretty gutsy call by the umpire, but I think he got it right."
Former D-backs reliever Juan Gutierrez officially absorbed the defeat, as the pesky Pollock drove in the tying run with a ground-rule double and scored the go-ahead tally in the sixth inning.