Sometimes it isn’t the heart of a champion, but a steely mindset. It’s remaining confident even when the losses pile up and the media counts you out and the fans begin to lose hope. It’s knowing you’ve done this before and you can do it again, even if conventional wisdom disagrees with you. It’s taking the last two months of the season and spitting on them, because you know there isn’t a single team that wants to see you come playoff time.

“The thing I’ve been impressed with is, it’s no alarm,’’ Jermaine O’Neal told the Boston Globe. “Nobody’s panicking. We understand if we play the way we’re supposed to play, we win.’’

The Boston Celtics had plenty of reason to doubt themselves, both this year and last. The basketball Grim Reaper had seemingly come for them, come to kill off the Big Three era with a rash of nagging injuries and old age, come to end championship-caliber basketball in Boston, at least for the time-being. But the Celtics had a trump card in their back pockets, the swagger of a champion, a shared confidence, or cockiness, an intangible stubbornness in their own abilities. They looked the Grim Reaper in his eyes, told him their time had not yet come, told him to visit the Cleveland Cavaliers and Orlando Magic instead.

You can crunch numbers for a long time, calculate the average margin of victory or the Hollinger rating or whatever else, but you can’t measure the belief these Celtics have in themselves, a belief which, I assume, comes from winning a championship. You can’t measure the value of looking at the guy in the locker room stall next to you and knowing you can rely on him, because you’ve done this before. When the Cavs drove over Boston with a Mack truck in Game 3 last season, at the TD Garden, it could have tore them apart. But pressure refines them, pressure makes them noble, and the Celtics didn’t lost to Cleveland again. When things went wrong for the Cavs, there was no past experience they could lean on, and thus adversity threw them into oncoming traffic.

“We’re going to have [adversity],” Doc Rivers told the Boston Globe. “It wasn’t an if. Be prepared for it. Embrace it, it’s a good thing. Enjoy the adversity. You find out who handles it well and who doesn’t, but even the ones who [don’t] at times, you hang in there with them, and eventually they’ll come through for you.’’

I’m not always a sucker for the intangible, but it’s hard to argue against the Celtics’ trust in themselves. You get the feeling they could lose 26 straight games (yet another Cavs reference) and still consider themselves the NBA’s best team. You get the feeling they could go down 0-3 in a series and still have no doubts they would come back. They’ve done this before and no matter what outside influences opine, no matter what advanced statistics or expert analysis tells them, think they can do it again. Sure, only five players remain from last season’s team, the same five who remain from 2008. But those five lead the rest. They instill a sense of calm during the furious storm of pressure.

For awhile, I thought Boston’s belief might be gone. I thought the Celtics might have too many new faces. I thought they might miss Kendrick Perkins for more than just his basketball talents. I thought the championship chemistry had been altered in a way that might be irretrievable. But it’s playoff time again and the Celtics are back to their old tricks, looking the Grim Reaper in his eyes and telling him it’s not their time.

Comcast has started a new feature called “Game Story,” a video summary of each game including player quotes and game highlights. Good, entertaining stuff.

We take a break from your regularly scheduled playoff programming to bring you the latest news/non-news about Doc Rivers’ contract situation.

The popular opinion has held that Rivers will take a break sometime within the not-so-distant future, perhaps even after this season. But Adrian Wojarowski believes Rivers might actually have interest in staying in Boston for longer, maybe even into the post-Big Three rebuilding (or, preferably, reloading) process. (WEEI)

Said Wojnarowski: “I know this, and I talked to Doc about this in the preseason: The appeal of being the Celtics coach for life has really improved for him. I think Doc knows he will never have it better than what he has right now in Boston, with this group of players and an ownership and a GM that he works great with, and a city that I think adores him and that he has come to love coaching for.

“I think it’s going to be really hard for Doc to walk away. And he talked in the preseason about thinking about going through the rebuilding, about having an interest in doing that — rebuilding around Rondo. … The idea that he would leave and all of a sudden sign up in Miami tomorrow or right away and have to come back and coach against [Kevin] Garnett and [Paul] Pierce and [Ray] Allen, I don’t see him doing that. I think his relationships and what Boston means to him, I think he’d sit out at least a year, and then I guess it would be open to anywhere.

“While I think there’s times Doc feels like maybe it’s time to walk away, I think in a moment of truth, leaving this organization is going to be really, really hard for him. Because I think deep down he knows he’ll never have it better than he’s had it here. That will pull on his heartstrings.”

Do we fawn over the starters’ performance or fret about the bench’s? Worry about Glen Davis’ lack of consistency, Jeff Green’s frustrating inability to make an impact and Delonte West’s “nobody wants to talk about it, but…” struggles, or marvel at a starting unit that carried its bench’s dead weight to a series sweep? Yes. On all counts, the answer is yes.

Admittedly, Boston’s bench looked better yesterday. But you wonder if the change was permanent, or whether the one game of light will fade back to darkness like it has too often this season. Gone was Glen Davis’ troublesome case of Chuck Knoblauch Syndrome, but I wonder if his high field goal percentage from yesterday is sustainable. Gone was Green’s unwillingness to mix it up on the glass, but his scoring struggles and utter inability to stay in front of Carmelo Anthony remained. Gone was Delonte West’s lack of aggression, but mixing it up with Landry Fields and Anthony Carter wasn’t exactly the type of aggression Doc Rivers was looking for.

On paper, the three players form a formidable trio. Big names and talented players, all of them. Capable of starting for more than a few teams, even. But for whatever reason, they haven’t meshed this season. At one point, we could blame that on injury. But Boston has gotten healthier and the bench remains stuck in the mud. The starters taketh, and the bench giveth away. That’s how the story has gone, on far too many nights.

Thankfully, the Celtics’ starters are operating on a different planet. Through three games against the Knicks, the starters had played 65.25 minutes as a unit. (Note: I would include the fourth game, but Basketball Value has not yet added it to the database). During that time, the starters outscored New York by 30.86 points per 100 possessions. While that number will inevitably go down against better competition and is inflated by a few factors, notably New York’s injuries and Boston’s fireball-hot shooting in Game 3, the starting five’s terrific play seems sustainable. Rajon Rondo has entered playoff mode, meaning he’s now 300% of the player he was in the regular season; Jermaine O’Neal’s body finally kept up its end of the bargain; Ray Allen shot the ball better this year than he has in his whole career, and that’s no small feat; and Paul Pierce and Kevin Garnett have been rejuvenated by the helping hand of good health.

The memories make me shudder. Garnett getting beat by Kris Humphries, getting burned by Al Harrington, surrendering 18 rebounds to Pau Gasol in a must-win game (somebody come to my house and check on me, please). Pierce’s mediocrity against Lebron James and later Ron Artest. The maddening thoughts that raced through my head as I saw two of my heroes heroically limp within six minutes of an NBA championship, thoughts of what if, thoughts of maybe they’re on the way downhill, thoughts of I hope that’s not how they go out.

The present makes me hope. There’s Pierce, humming for 38 points against Carmelo Anthony, soaring for dunks like he were back playing for the Kansas Jayhawks, dictating his own shots rather than being forced into bad ones by his defender. There’s Garnett, earning the second-most votes for Defensive Player of the Year, moving well enough for Doc Rivers to call a crunch-time low-post clear-out, snuffing out opponents’ scoring opportunities on the regular. For as much as this Boston Celtics season has been marked by injuries—debilitating ones to Shaq and Jermaine O’Neal, nagging ones to Rajon Rondo and Glen Davis and a season-crippling one to Delonte West, among others—the two men who led Boston to the 2008 title are running and jumping like young bucks. It’s the biggest difference between this year and last, the most valuable improvement from the team that coulda, shoulda.

When the Celtics needed a bucket last night, when the Knicks had closed a 23-point lead to four, there was Pierce, passing up a good shot to get a better one, gliding by New York’s defense with the long, nimble strides of a born-again youth. When they needed some breathing distance, there was Garnett hitting jumpers. When they needed stops, which happened not so much last night as in the first two games, there was Garnett, suddenly omnipresent.

So much was written and spoken about Boston’s fall from grace, about Kendrick Perkins’ relocation meaning the end of Ubuntu, about how Danny Ainge might have shipped away Boston’s title chances in one fell swoop. Lost in all the worry was the continued health of Boston’s core, the players who matter the most, the ones who allowed Boston to sweep New York despite a bench that was more hindrance than help. In that regard, at least, the Celtics are in a better place than last year. Always willing, Boston’s bodies are once again able.

In the playoffs, because coaches cut down on their rotations, starters take on a greater significance. If that means the bench’s struggles matter less and and the starter’s rejuvenation matters more, count me in. Still, Doc Rivers would love to see his bench join the party on a more consistent basis.

Bill Walker knew not to expect the regular season Celtics. No matter what Boston looked like during their end-of-season funk, he knew, they would become gladiators come playoff time. (ESPN Boston)

“Those guys have got nine lives,” Walker said of his ex-mates. “It seemed like every time we got them down, or made a run, they always had another trick up their sleeve.

“You see them on film and they look like they’re old and slow, until you get out there and they’ve got a 7-foot-1 power forward [Garnett] who is more mobile than you think and a point guard [Rondo] who is an emerging superstar and two guys [Pierce and Allen] who never miss big shots. Then you’ve got JO [O'Neal], who wants to win so badly, and then you realize, they’re hungry.”

They’re hungry. And damn talented. And damn experienced. Miami, the Celtics are coming for you.

I knew Anthony Carter would lead a comeback, I just didn’t know when. Superstars rarely fade without a fight. But not even Carter’s onslaught (of sorts) and his teammates’ surge of energy could get New York back into the game. Not after a first half that was more surgery than blowout.

If Friday night was extraordinary, with Paul Pierce and Ray Allen combining to hit 14-19 threes and Rajon Rondo compiling just the eighth 20-assist triple double in NBA history, the only thing extraordinary about today’s first-half dismantling was the ordinary, dull and methodical fashion Boston used to end New York’s season. There was nothing special about the way Boston played, nothing the Celtics couldn’t presumably repeat every night, no record-setting feats, no historical subtext, nothing but the cold, steady hand of an experienced killer.

The Celtics immediately turned from old and gray to wise and experienced, posting the first series sweep of the Big Three era, Boston’s first series sweep since Larry Bird still wore the number 33, and the only sweep of any team in this year’s first round. This team didn’t resemble the Celtics who limped into this year’s playoffs. No, this was the Celtics who helped nudge Lebron James out of Cleveland. This was the Celtics who convinced Otis Smith to blow up his entire roster. This was the Celtics who have been to two Finals in the past three seasons and don’t believe they’re done adding to that tally.

Rajon Rondo could have been in Minnesota, or Idaho, or Podunk, or wherever else Mike D’Antoni wants to see him play, and Toney Douglas still wouldn’t have had a chance. Playoff Rondo is gourmet macaroni and cheese to Regular Season Rondo’s Easy Mac, a beast of the same species but completely different genetic makeup. He’s able to carry his teammates to a different level, and given that he’s working with three Hall of Famers, given that Kevin Garnett and Paul Pierce are far healthier than they ever were last postseason, the Celtics can’t mind their positioning heading into the second round.

When the Knicks drew within four points in the fourth quarter and the crowd had woken to a frenzy of false hope, Pierce came around a screen. An open jump shot shouted his name but Pierce pretended like he didn’t hear the screams, knowing another option was more enticing. He lowered his head instead, found his way to the bucket for an easy lay-in, the shot he wanted rather than the one that was available. It was a bucket Pierce wouldn’t have made last year, a bucket that resembled Game 6 against Detroit in 2008 or Game 5 against LA during the same year, a bucket that was our latest reminder that he and Garnett are younger this year than they were last year, not in age but certainly in mobility.

Sure, New York was overmatched to begin with, and even more so when Chauncey Billups went down and Amare Stoudemire’s shield of armor developed a chink. But this series wasn’t about New York’s return to the playoffs, nor was it about Carmelo and Amare’s first opportunity to win together; it was about a Celtics team too stubborn to recognize its own mortality. The Knicks were destined to be one and done. They were a novelty because of their star power and location, but not a basketball team capable of winning four playoff games. Meanwhile, even after the Celtics ended the regular season with a limp, we always knew their path would ultimately lead to Miami. The Knicks were only a speed bump along that road.

A comeback briefly stifled Celtics fans’ excitement, but Boston still did more than enough to send a message: Miami, we’re ready. Whatever happened in the regular season, it means nothing. You’re on our turf now, whether we play in South Beach or Boston, because the playoffs are our time. Lebron James and Dwyane Wade have accomplished so much in their careers; individual trophies, Olympic gold medals, All-Star appearances, All-NBA teams, so many wins, so many accolades, so many highlights, and so much respect. But neither one has ever beaten Boston in a seven-game series. The Celtics remain an obstacle neither Wade nor Lebron has ever conquered. Of course, they were trying alone. This will be their first attempt while operating as a tandem.

After a week of rest afforded by their sweep, the Celtics will be ready. Two narrow series-opening wins did nothing to dispel the notion that Boston’s prime was gone, to subdue the growing feeling that the Celtics were championship contenders in reputation only. But the Celtics showed another level in the Big Apple, one that held New York to 34.1% shooting in an elimination game, one that made Carmelo Anthony sound proud of being swept, one that assured New York’s postseason win drought would reach at least 11 years, one that reminded everybody: the Heat have home court advantage, but the path to the NBA Finals still goes through Boston.