One of the oldest clichés on the planet, like many clichés, has a nugget of truth: “If it ain’t broke, don’t fix it.”

Until this spring, Major League Baseball was broke.

The games, even for those of us who have loved and followed the sport since childhood — which in some cases was a long time ago — had simply become too long. Way too long. And, frankly, boring. There were strikeouts and walks and the occasional home run. There were batted balls that would once have been hits that instead went directly to the short-fielder — just like in softball! — rather than through a hole.

You name something that could slow the game down — or bring it to a complete halt — and it was happening: pitchers stepping off the rubber; pitchers throwing to first base; batters stepping out of the batter’s box on every pitch; nonstop trips to the mound by the pitching coach, the catcher or the entire infield.

Once, nine-inning baseball games rarely lasted more than two hours and 30 minutes, and occasionally finished in under two hours. But game times began to creep up beginning in the late 1970s, and by 2014, the average game was taking more than three hours.

Baseball realized it had a problem. Finally, some baby steps were taken: Relief pitchers had to face at least three batters; trips to the mound were limited to six a game — not counting, of course, a pitching change.

Still, in 2022, the average nine-inning regular season game lasted three hours and three minutes. Playoff games took significantly longer.

Finally, after years of discussions, committees and arguments followed by more argument, the sport made serious changes this season: instituting a pitch clock and limiting the number of times a batter can step out of the box and the number of times a pitcher can “disengage” — step off the rubber and/or throw over to a base. The bases were enlarged to encourage more stealing and the softball-like shifts were eliminated.

Many of the rules had been tried out successfully in the minor leagues. Even so, the so-called “purists” worried about games being decided by clock violations and the game not being as “timeless” as it once was. Sure enough, an early exhibition game ended on a pitch-clock violation and the screaming grew louder.

Then, the regular season started. And everyone adapted. Through the all-star break, games were taking an average of two hours and 38 minutes — down 25 minutes from last season. Steals were up, batting averages were up and, most important, fan enjoyment was up.

MLB was so proud of its new product it began taking out TV commercials reminding fans how exciting the new game of baseball was for all to see.

They were right.

But during the break, when MLB Commissioner Rob Manfred and players union head Tony Clark met individually with the media, Clark suggested that some players feel that the new rules should be tweaked for the postseason by extending the pitch clock. He did not suggest re-shrinking the bases. Thank goodness for small favors.

I have one reaction to this: Stop!!!

The game has (finally) fixed most of what was broke; don’t re-break it.

There is no reason to bring dawdling back into the game and there’s no reason to play postseason games under a different set of rules than the regular season. Is there more pressure in the postseason? Of course there is, but that’s part of the deal: You want to win a championship, you deal with extra pressure.

One rule does change in baseball’s playoffs: The absolutely ridiculous ghost runner on second base in extra innings mercifully goes away. If MLB wants to be consistent with its regular season vs. postseason rules, there is an easy fix: Get rid of that absurdity entirely.

Baseball has always been the slowest sport to change rules. There is a notion among many that it was God who decreed there be 90 feet between bases and 60 feet and six inches from the mound to home plate.

I’m okay with both those notions. It’s worth remembering that 55 years ago the pitching mounds were still 15 inches high. Then run-scoring dropped to almost zero; only one American League hitter (Carl Yastrzemski at .301) hit .300 and Bob Gibson pitched to an ERA of 1.12. Attendance — especially in the American League — dropped significantly. So, baseball lowered the mound to 10 inches and has never looked back.

There was no designated hitter until 1973 and it took almost 50 years for the National League to join the American League in allowing the DH.

Change came and baseball not only survived, it thrived. Commissioner Bowie Kuhn declared in 1975 that free agency would kill baseball. Not exactly.

The sport had to be dragged kicking and screaming into using the pitch clock and the other recent adjustments. Suddenly, the broken game looks almost fixed.

It is important that these same trends continue in postseason. Games that don’t start until almost 8:30 p.m. Eastern time should not end after midnight. (They should still start earlier, but there are certain things TV simply won’t allow.)

In his All-Star Game news conference Manfred said he liked the effect the new rules have had on the game but didn’t rule out postseason tweaks.

Let me repeat myself: STOP!!!

Manfred makes more than $11 million a year as commissioner. This is one of those times when he needs to earn that money by making it clear to all that the changes are working and should not be messed with during the postseason.

Thirty years ago when the owners were trying to kill the player’s union by refusing to collectively bargain with them, I asked Tony La Russa, then the manager of the Oakland Athletics, if he worried about the future of the sport.

He shook his head. “No, I don’t,” he said. “Because, in the end, the game is better than all of us.”

That magic was lost for a number of years. The new rules have helped bring it back, especially for those of us who look forward to watching baseball on a daily basis from March through October.

Let’s not re-break what is no longer broke.