LOS ANGELES -- It's the sixth inning of Game 3 of the National League Division Series presented by T-Mobile in Phoenix. Dodgers first baseman Cody Bellinger is three hitters away from one of the biggest at-bats of his rookie season.

D-backs right-hander David Hernandez is on the mound, facing Dodgers leadoff man Chris Taylor. But Bellinger is a step ahead. Wisely, he assumes he won't be facing Hernandez. In an elimination game where all matchups are on the table, Bellinger knows there's a much better chance he will face his opponents' top lefty instead.

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So Bellinger turns his back on the game for a moment, retreating instead to a pair of iPads set up in the rear of the Dodgers' dugout. He's only faced Andrew Chafin three times. But unlike, say, two decades ago, that's no excuse for a Major League hitter being underprepared. There's a wealth of information to be gleaned simply from watching Chafin face fellow left-handed hitters with tendencies similar to Bellinger.

"The technology definitely helps," said Bellinger, whose Dodgers will host Game 1 of the NL Championship Series presented by Camping World on Saturday. "Nowadays ... the bullpens, they've got a lot better stuff, and you need more ways to prep."

Bellinger cues up video of Chafin facing the Rockies' Charlie Blackmon in the NL Wild Card Game. Chafin begins the at-bat with a pair of sliders, comes back with a fastball, then throws four consecutive sliders. On the seventh pitch, Blackmon pops to center.

Five days later, Chafin is summoned to face Bellinger in the ninth (after Hernandez escaped the sixth and Bellinger faced Archie Bradley in the seventh). Sure enough, he opens the at-bat with a pair of sliders, followed by a fastball. Chafin comes back with two more sliders, and with a 2-2 count, Bellinger lofts a flair to the opposite field. It lands barely out of the reach of David Peralta for a single. (Peralta atones with a brilliant throw to the plate to get Justin Turner .) Nonetheless, Bellinger's homework paid dividends in the form of a ninth-inning knock in a crucial playoff game.

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So what exactly is Bellinger looking for when he locks into study a certain pitcher?

"You just watch what he has," Bellinger said. "From that aspect of it, you don't try to do too much. You just need it to prepare for your at-bat. ... It can help you a little bit to see how the ball moves."

No doubt, technology has changed the sport. But that evolution has taken place largely off the field -- in video rooms, in clubhouses and away from the park altogether.

"It's around the clock," Dodgers skipper Dave Roberts said. "They have iPads, they have information, videos that they travel with on the airplane. ... There's also a balance of keeping your eyes on the game and seeing the game with your own two eyes, getting a feel for it. In balance, I think it's great."

Last March, Major League Baseball approved the use of the iPad Pro, giving teams the benefit of preparing via video. (Per league rules, the devices cannot connect to the internet or stream live video during play.)

Use of the devices extends beyond the ballpark. Have a spare moment on the bus? It might be time to check out that day's starting pitcher.

"They can watch from their hotel rooms, from home, different angles, different pitchers and all the stats that any player might need," Roberts said. "Obviously they can come in, in-game, and watch their at-bats, and that can be beneficial."

Padres Hall of Famer Tony Gwynn pioneered the use of video study. His obsession -- at a time when few others were doing so -- gave him a distinct edge.

Now? As Bellinger points out, it's a two-way street.

"It helps us, and it can help opposing pitchers for other teams, too." Bellinger said. "It can be an advantage for both teams that kind of evens out."

Indeed, video use -- whether pregame or in-game -- has become so ingrained across the sport, it's no longer a competitive advantage by itself. But the savviest video watchers put themselves in position to succeed by doing so.

"Having a game plan prior and knowing tendencies, that adds huge value," Roberts said. "It's a credit to our guys that they're very open to information."