Collapses do not belong exclusively to this era. You don’t need to do more than identify the 1914 Giants, the ’51 Dodgers, the ’64 Phillies, the ’69 Cubs and the ’78 Red Sox to know what the subject is.

But there has been a cluster in recent seasons that is hard to find at any other time in history. The 2007 Mets blew a 7 1⁄2-game with 17 to play and the 2008 Mets failed to hold a 3 1⁄2-game edge with 17 to go. The 2009 Tigers led the Twins by three games with four remaining and ultimately lost a one-game playoff to Minnesota to miss the postseason.

And 2011 was a year that will live in collapse infamy. The Braves led the Cardinals by 10 1⁄2 games for the wild card on Aug. 25. On Sept. 3, the Red Sox beat the Yankees to move 30 games over .500, 1 1⁄2 games ahead of the Yanks in the AL East and nine games ahead of Tampa. At that moment, Boston had better than a 99-percent chance of making the playoffs. Like the Braves, however, Boston epically failed to reach the postseason.

YANKEES BOX SCORE

So is this all coincidence that we have this compilation of collapses and two of the greatest ever in one season? Or is there something more going on? The most obvious item is that more teams make the playoffs now and, thus, pure math will show there simply are more races per year that can be blown than in the past. This year there is a second wild card in each league to win — or not.

But it is deeper than that. Before wild cards, more teams used to concede earlier in the season by making trades or calling up prospects. But the carrot of the wild card(s) keeps a greater number of teams chasing potential pipedreams and, thus, deepens the pool for a shocking late run.

For example, the Yankees led the AL East by 10 games on July 18. That is by far the biggest lead any first-place team has had this year (the Dodgers’ 7 1⁄2-game lead over the Giants in May is the second). The trade deadline was fewer than two weeks away, and without wild cards there would have been an impetus for the other AL East clubs to sell. Instead, all four remained buyers.

When this weekend began, both Tampa Bay and Baltimore were 6 1⁄2 behind the Yankees. It is the kind of lead that history says is comfortable. But recent history does suggest not getting too comfortable.

And if the lead keeps narrowing then Casey McGehee’s new team will have to cope with something Casey Stengel’s never did: the relentless 24/7 flow of noise. Think about how New York has been besieged with Linsanity and Tebow. Now imagine the inexorable cacophony that would exist on sports radio, Twitter and every other competing outlet that dispenses opinion and animus. I do think that was a factor in those collapses last year: The inability to escape the pressure and the realities of a shrinking lead even long after the games were done. There is little — or maybe no — sanctuary for athletes to escape to if they are trapped in the collapse vortex.

The Yankees are not yet in those clutches and may never be. And, remember, when the season began the anticipation was that the AL East would be very competitive. Any Yankee would have signed up for a 6 1⁄2-game lead entering the first weekend of August.

But on July 18, according to coolstandings.com (which runs millions of simulations of the season to derive odds), the Yankees had an 86.5percent chance to win the AL East and a 96-percent chance to make the playoffs. That was down to 83/92.2. Again those are odds greatly favor the House … That Ruth Built.

Still, the Braves moved into September 2011 with a 97.7-percent likelihood of reaching the playoffs and the Red Sox 99.4. So there is precedent here.

“Maybe they won’t get in [the playoffs],” Red Sox manager Bobby Valentine said of the Yankees just last weekend. “Who knows? Crazy things happen in this game.”

Valentine has reasons to try to unsettle the Yankees. But there items are to suggest that the Yankees are not simply heading to Four Corners to run out the season.

At the time they built a seemingly commanding double-digit lead, the Yankees had lost just one position player for an extended period — and that was Brett Gardner, who might be their least-important regular. Since then, however, Alex Rodriguez was lost for six-to-eight weeks, and Nick Swisher and Mark Teixeira incurred, at the least, short-term injuries.

Pretty much every team endured pitching injuries this season, including the Yankees (Mariano Rivera, Michael Pineda, Andy Pettitte, etc). But by having their offense intact, the Yankees weathered the pitching losses better than others and also did not overexpose players like Eric Chavez, Andruw Jones and Jayson Nix, who instead were used in specific roles in which they could thrive. We will see what happens if they have to step outside their comfort zone in games of more magnitude.

Meanwhile, similarly to how Boston’s and Atlanta’s pitching ran out of gas in 2011, the Yankees relief corps now has shown cracks. One early-season revelation, Cory Wade, already is in the minors, and Boone Logan, Clay Rapada and Cody Eppley — whose success made the Yankees bullpen so deep in the first half — have struggled of late. Suddenly, Joba Chamberlain is not a luxury. The Yankees need him to be good and David Robertson to rediscover more of 2011.

As for the rotation, there is a perception vs. reality thing. The reality is that Yankee starters have the third-best ERA in the AL. The perception is that there is not a trustworthiness to this group, especially with Pettitte absent.

It is worth noting that the Rays’ rotation, which served as the backbone to their late run to overcome the Red Sox last year, is humming again, while the Red Sox still have those nine games left against the Yankees to potentially do some head-to-head damage.

Historically, the kind of lead the Yankees have today bodes well for making the playoffs. But there has been more of a different kind of history the last few years than ever before. So we will see if the Yankees can avoid being part of the collapse conversation.

joel.sherman@nypost.com