Frustration began to mount soon after the 2020 MLB season got underway last summer. Without in-game video available to major league hitters for the first time, many found themselves at a disadvantage at the plate.

They struggled.

And then they vented. Mostly, players chirped to their agents, and then those agents called the league office to complain.

What began as a potential tweak due to sign-stealing concerns became a ban on video altogether once the pandemic hit. Unlike those of us viewing from home, players could not watch a replay of their at-bat or a pitch they threw until after the game was over. It was a departure from past practices and a tough adjustment for some star players.

"We did hear from some people multiple times," MLB executive vice president Morgan Sword said last week. "We understood the frustration. It was one of many disruptions to normal [baseball] life last year."

As Philadelphia Phillies catcher J.T. Realmuto said, "Video is so important, to have that immediate feedback. It helps pitchers, catchers, hitters, and lets you know if what you're seeing is right or wrong."

Before 2020 -- and the sign-stealing scandal ignited by the Houston Astros -- players were able to go back into the clubhouse into a video room and replay their last at-bat. They could analyze their swing or simply how they were seeing the strike zone that day in real time, and some players struggled with the abrupt change.

"It's a fine line," said Chicago Cubs first baseman Anthony Rizzo, who hit .222 last year. "You didn't want to make excuses, and there are no excuses, but for 10 years in the big leagues I've had access to video. I'm a huge in-game adjuster. Pitch to pitch, at-bat to at-bat."

For others, it wasn't a big deal.

"It's not going to change anything for me," Brewers star Christian Yelich said recently. "I'm not a big in-game-video guy. I just don't like it. I feel like whatever swing you have that day is the one you have."

But it's Rizzo's sentiments that echo what many players said when interviewed for this story: They didn't want to come across as excuse makers but were adamant about wanting in-game video to return.

The league was sympathetic to their arguments and struck a compromise with the players' union for 2021. A new system will be in place for Opening Day that should satisfy three needs: allowing players to watch previous at-bats, eliminating the possibility of stealing a catcher's signs and all of it happening in a safe environment during the pandemic.

"I think it's significant," Milwaukee Brewers manager Craig Counsell said of in-game video returning. "And when it's a tool you've been using for the bulk of your career, and it's gone, you feel empty a little bit. It's the right thing to do."

The league is revamping its iPad dugout program to include in-game video this season. iPads have been allowed in the dugout, but only with pre-uploaded materials. A player could look up a pitcher's or hitter's past tendencies but could not access anything that occurred during that game.

That's changing.

"We knew it was important to find a solution for this issue for 2021 and that we were likely in the same place regarding the pandemic," Sword said. "We don't want people in the video room."

The league developed software that would meet player concerns while keeping small groups from gathering in the video room. Beginning on Opening Day, a player's at-bat will be uploaded to the iPads in the dugout soon after his plate appearance. To prevent sign stealing, the video will be edited to begin as the pitcher is about to throw the ball.

"The clips don't start until after the catcher has given the signs," Sword said.

Each clip will contain a combination of broadcast and MLB-owned cameras that upload the play to the new software program. It is cut at the point after signs are exchanged between catcher and pitcher and sent to the iPad on a half-inning delay. There were discussions about blurring the signs, but this system eliminates them from the equation.

"That's great," Rizzo said when informed of the new technology. "The biggest thing with video for me, I need to see it to make sure I was right [seeing the strike zone], but if I'm wrong, I can make the adjustment right away."

There's little doubt that position players will get the most out of in-game video returning, especially when compared to starting pitchers. The latter group was less likely to run back into the clubhouse to analyze one or two pitches between innings, but the time between at-bats made it much easier for hitters to check in with their video guy.

"As a pitcher, I'm throwing 100-plus pitches, and I'm not really interested in going back and looking at that stuff," White Sox starter Lucas Giolito said. "I'll save that for after the game. A hitter has three to four at-bats. They're all hugely important."

One pitcher noted that he might sneak a peek more often now that he could do it from the dugout, and that managers might also prefer the new system.

"I think it's a plus because the negative was guys were going in to look at their at-bats, which means guys weren't out there to watch the game that half-inning," Giolito's skipper, Tony La Russa, said.

There have been stories of the video room being more crowded than the dugout during games, but that will end.

"The iPad in the dugout helps, for sure," Counsell said. "Players use the video room as a calibration, really. To know where pitches are in the strike zone. It's so useful for hitters. More than mechanical adjustments they are making by seeing video. It's that calibration they'll be allowed to make."

The biggest potential losers with the new program? Umpires. One noted how much less he heard from players last year after their at-bats because they couldn't watch them instantly. One pitcher jokingly said that 80% of in-game video was used to confirm an umpire got a call wrong. A hitter denied that accusation, but only by saying 80% was too high.

Either way, most parties are happy with the new system.

"The players have been great on this issue," Sword said. "We've tried hard to make it up to them by providing them a solid piece of technology. We're probably going to be working with them to make sure we nailed this."

However it's applied, an old saying became readily apparent for players last year: You don't know what you have until it's taken away. The pandemic season of 2020 was rough in so many ways. And 2021 will begin the same way 2020 ended, with players following a slew of health and safety protocols. But at least they have their in-game video back.

How much difference will it make?

"It was different for every hitter," Realmuto said. "For me, I was in the middle. I would rather have video. It wouldn't kill me not to have it, but I've had conversations with hitters, and it was pretty devastating for them not to have that immediate feedback."

After the Astros scandal erupted, the league knew it had to curb ways in which teams were stealing signs. Houston, among other teams, showed how being able to see the catcher's signs in real time or soon after on video could have a major impact on the field. To stop the issue during the 2019-20 offseason, MLB went to work with the players' union on launching a video system that would eliminate electronic sign stealing. The talks stretched into spring training.

Then the pandemic hit.

"We were in the middle of working through that with the union, and it all screeched it to a halt," Sword said.

As talks on the subject resumed during baseball's shutdown, it became clear they had to start from scratch again, with going into the clubhouse to watch video no longer a possibility at all.

"The operations manual in 2020 prevented any coaches or players from going into the video room for any reason," Sword said. "We didn't want people in small enclosed spaces together."

Talks then shifted to how to make a system work in the dugout, but the software required a tech guy to be with the players throughout the game.

"Playing safely was our No. 1 priority," Sword said.

While it's impossible to prove just how much performance was affected by the lack of video, there's no arguing that career-long routines had been altered. By September, J.D. Martinez and Javier Baez were among the star players to go public with their frustrations.