The NBA store started selling Oklahoma City Thunder “Beat the Heat” t-shirts. An NBA.com writer used 1,000 or so words to describe why a Heat-Thunder Finals would make basketball better. Reporters have already asked Doc Rivers to reflect on the Big Three era, as if it is already over. Everyone seems to be counting out the Boston Celtics, who need just one more win to make their third NBA Finals appearance in the past five seasons.

Six games have showed us a lot, but the most obvious takeaway from the first 298 minutes of this series is that these are two even teams. The Heat won blowouts in Game 1, when the Celtics had just one day of rest/preparation and were playing their 14th playoff game in 28 days, and Game 6, when LeBron James became a mixture of Michael Jordan, the Grim reaper and that huge dude from Happy Gilmore with a nail stuck in his head. The Celtics won a blowout in Game 3, when they returned home down 0-2 and were playing with a level of desperation the Heat simply couldn’t match. The other three outings have been hotly contested, including two overtime decisions and a four-point Celtics Game 5 victory which easily could have gone the other way.

Despite the Heat playing at home, there’s no real reason to discount the Celtics. They already stole a crucial game in Miami, Game 5, which both teams treated similarly to a Game 7. They were perhaps a missed foul call in Game 2 from winning four straight. Most importantly, they are a crew of gritty, accomplished veterans who know how to break into a visiting stadium wearing black ski masks and steal every valuable possession on their victorious way out. (See: Game 5.)

As CSNNE’s Rich Levine wrote in his fabulous column following Game 6:

Can the Celtics do it?

Come on, that’s a stupid question. Of course they can do it. If you don’t believe the Celtics can go down to Miami, reverse the fortunes of Game 6 and shock the world one more time, then you’re believing all wrong. You know nothing about this team, the resilience of champions, the level of grit, balls, fortitude and obscene levels of pride and skill that go into a Hall of Fame career, into making it this far in the first place. You don’t know how much this team loves and cares about Doc Rivers, about each other, about their fans and about themselves. You didn’t see the tears running down their faces in the moments after that Game 7 loss two years ago in LA. The feeling that they’d blown their last chance to separate themselves from the hordes of one-hit championship wonders and into another stratosphere of NBA history. As individuals, and more importantly, as a team.

Motivation should never be a factor entering a Game 7, but the Celtics are in a different spot than Miami. LeBron James will be torn apart if he loses tonight, but he’ll have plenty of more chances. These Celtics won’t. They’ve extended a three-year window to five, but even cats die after their nine lives expire.

I think Levine’s point about one-hit championship wonders is critical. One ring wasn’t enough for the Celtics’ nucleus. The Big Three understand that every other championship nucleus in franchise history captured at least two rings. They know how history smiles upon teams with at least two titles but tends to overlook those with one. Paul Pierce has always said that multiple titles are his goal and tonight, this year, is his next and perhaps final chance to replicate his 2008 feat. You don’t think that matters to Pierce? To Allen? To Garnett? You don’t think they want to differentiate themselves from one-hit wonders like the 2011 Dallas Mavericks, 2006 Miami Heat, 2004 Detroit Pistons and 1983 Philadelphia 76ers, the only four teams in the last two decades to stop after just one title? You don’t think Pierce is sitting in his hotel room as I write these words, visualizing scoring 30 points on LeBron tonight, rubbing his left ring finger and thinking about how nice it would be to earn a second diamond-studded rock sometime within the next couple weeks? You don’t think he understands this is (actually, this time) his last chance?

I don’t understand why Shaun Powell or anybody else would feel compelled to write that “basketball wins” if the Celtics lose. I’m sure ratings win if the Celtics lose, David Stern wins if the Celtics lose, the NBA as a profit-seeking organization wins if the Celtics lose. But basketball, in its purest form? The Celtics have spent the past five seasons succeeding with a team-oriented concept in a league where that’s rare. They are dedicated enough and professional enough to reach the Eastern Conference Finals with two 36-year old starters and another one who’s 34. They are defensive-minded enough that Doc Rivers, when asked what better defense the Celtics needed to use in the wake of LeBron’s 45-point Game 6 assault, responded, “The one we always play.” They treat the game with a level of respect that displays itself in offseason workouts, which reveal themselves in the Celtics’ 17th playoff game in 34 days, during which Garnett — veteran of 50,000-plus NBA minutes — had 26 points and 11 rebounds.

This isn’t anything against the Heat, a worthy Eastern Conference champion should they win tonight, a hard-working and selfless bunch themselves. But basketball doesn’t win if the Celtics fall. Basketball would lose one of the shining examples of how special the combination of hard work, dedication and a deep bond created by a shared goal can become.

We are here again, for the second straight series. Tonight could mark the end of the Celtics’ season, and perhaps an era, or it could become the next improbable win in a schedule filled with them. Whatever happens, we shouldn’t be surprised.