How effective have Major League Baseball's new pace-of-game measures been in the season's first month? So effective that officials from MLB and the players' union will not implement the series of tardiness fines that were supposed to go into effect Friday, according to sources familiar with the discussions.

The two sides have had "dialogue" about relaxing or eliminating most of those fines, said Tony Clark, executive director of the Major League Baseball Players Association, because the results so far have been so good without them.

Through Wednesday, the average time of a nine-inning game was down to 2 hours, 53 minutes and 40 seconds, according to MLB. It's a drop of more than 8½ minutes from the 3:02:21 average for the full 2014 season, and of more than seven minutes compared to the average of 3:01 at the same point last season.

One factor at play in the reduction of time of games: Hitters must keep one foot in the box between pitches throughout their at-bats. Jake Roth/USA TODAY Sports

If this decrease holds, according to the Elias Sports Bureau, it would be the largest drop in average game time, from one year to the next, since 1963, when game times were cut from 2:34 to 2:25.

When the new pace-of-game measures were announced in February, games in April were set to be part of a phase-in period for players to get used to changes such as between-inning timers and rules requiring hitters to remain in the batter's box throughout their at-bats. Then, on May 1, a series of fines ranging from $100 to $500 was scheduled to go into effect.

However, Clark told ESPN.com that the union and MLB are in talks to "find common ground" on adjustments to the original agreement. And MLB senior vice president Chris Marinak, who is overseeing the pace-of-game initiatives, said it's likely the fines will be levied only if there are "flagrant violations."

"The idea here," Clark said, "was to effect some positive changes in habits, and to see if, by doing so, we could also shorten the length of games and perhaps improve the pace. And the result is that a lot of [players] have done exactly that. ... So to penalize guys just to penalize them doesn't make a lot of sense."

Instead, MLB is likely to continue to monitor games, as it has done so far, and send letters to players it believes have been in violation of three measures introduced this season that directly impact players:

• With certain exceptions, hitters must keep one foot in the batter's box between pitches throughout their at-bats.

• Each ballpark now has between-inning countdown timers to ensure that the next half-inning starts promptly. The timers are set at 2 minutes, 25 seconds for most games, 2:45 for nationally televised games. Pitchers and hitters have been encouraged to be ready to go when the clock reaches 20 seconds.

• Relief pitchers entering a game are also required to adhere to the same countdown timers, which begin at the moment they leave the bullpen and set foot on the warning track. Pitchers who aren't ready to pitch when the timer reaches zero, regardless of how many warm-up pitches they have thrown, are considered to have violated the new rules.

In addition to those three changes, managers can now signal instant-replay challenges to umpires from the dugout area instead of from the field. That change wasn't made specifically to improve the pace of play, but officials believe it has helped to make the challenge system more efficient this season.

Commissioner Rob Manfred told ESPN.com earlier this year that baseball isn't focused on game times as an accurate measure of its progress in this area.

"I'm really not thinking about this in terms of average game time," Manfred said. "It's not like I have in my head I want to get from 3:02 to 2:58 or 2:55. That's not what it's about for me.

"What I hope happens," he went on, "is that, at the end of the season, knowledgeable baseball writers and fans are saying, 'You know, they got this one right. There's a crispness to the play. They've cleaned up some dead time in the game. And maybe best of all, we feel like they were responsive to what people were saying about the game.'"