Dunkin' Donuts Park in Hartford, Conn., is the home of the Yard Goats. (Jessica Hill/AP)

Baseball’s unwritten rules reared their notorious head Tuesday evening when a successful bunt in a minor league game led to the benches clearing.

The bunt, with one out in the ninth inning of a game the visiting Trenton Thunder was losing 3-0, broke up a combined no-hitter by four Hartford Yard Goats pitchers. Hartford got the next two batters out to win the game by that score, but afterward Yard Goats starter Rico Garcia expressed resignation about the play made by Trenton’s No. 9 hitter, outfielder Matt Lipka.

“It is what it is,” said Garcia (via milb.com), who pitched six dominant innings for his Class AA club. “[Lipka] was doing what he had to do. And we were really passionate about getting the no-hitter. It is what it is. I can’t really speak for what he was trying to do or what he was trying to accomplish. It’s unfortunate we couldn’t get the no-hitter. Emotions were high after.”

Laying down a bunt to break up a no-hitter, even unsuccessfully, has long been considered within baseball culture as a violation of those unwritten rules, which generally apply to forms of conduct.

Other violations include stealing bases with a significant lead or when well behind and expressing too much frustration with teammates’ mistakes or too much joy at opponents’ failures. On the flip side, the unwritten rules appear to encourage hitting a batter with a pitch if the opposing team had previously done the same thing with suspected intent.

Not everyone is on board with these rules, particularly among those observing baseball as opposed to playing it. In the case of Lipka’s bunt, more than a few pointed out that the close score validated any attempt to get on base.

But not only did the Hartford players take exception to the play, Lipka received death threats on social media, according to NJ.com.

The unwritten rules were invoked in a major league game last year between the Orioles and Twins when Minnesota starter Jose Berrios had a 7-0 lead and was two outs away from a one-hit shutout. Baltimore’s Chance Sisco took advantage of a defensive shift and laid a successful bunt down the third base line, provoking subsequent gripes from his opponents.

“I don’t care if he’s bunting. I just know it’s not good for baseball in that situation. That’s it,” Berrios said

“Nobody liked that. No, no, no. That’s not a good play,” asserted Twins outfielder Eddie Rosario.

Sisco, though, defended his bunt, saying, “If they’re going to shift, I have to take it right there in that spot. We got bases loaded right after that. … We’re a couple runs away from being back in that game.”

Then Minnesota second baseman Brian Dozier countered that part of his team’s frustration was that, earlier in the game, the O’s “didn’t hold our runner on,” which the Twins took to mean that “they didn’t want us to steal” in a lopsided game, “so we didn’t steal.”

“We could have very easily stolen and put up more runs, so therefore in return you don’t bunt,” Dozier said.

He added, “Everyone just thinks, ‘He’s whining because they bunted against the shift.' That’s how baseball is played. That’s just how the game is played. That’s just how it is.”

In recent years, unwritten rules about “showing up” opponents by taking too much overt joy in big plays have been tested by players who want to show emotion. MLB appeared to take their side last year by rolling out an ad before the playoffs that had the tagline, “Let the kids play.”

During that postseason, TBS analyst and former MLB pitcher Ron Darling struck an old-school note when he criticized the Red Sox’ Andrew Benintendi for stealing second while Boston had a nine-run lead over the Yankees. Darling was further vexed later in the game, when Benintendi swung at a 3-0 pitch.

“There used to be a book. There’s no book anymore,” Darling told TBS viewers. “Everything’s gray. But I would find that offensive, personally.”

There appeared to still be a book on Tuesday, at least as far as the Yard Goats were concerned. They were unable to throw the book — or anything else — at Lipka when the teams met again Wednesday because, for some reason, he was held out of the starting lineup.

Read more:

MLB’s netting dilemma: With current standards, danger is just a second away

Nationals walk off White Sox, with late heroics overcoming another bullpen collapse

Heavyweight champ Andy Ruiz Jr., once bullied for his weight, says ‘people can relate to me’