The Miami Heat – and guard Dwyane Wade in particular – deserve great praise for their gumption and courage in coming back from a 13-point deficit in the final six minutes to win Game 3 of the NBA Finals, 98-96, on Tuesday night. But let’s not forget another key element: Dallas choked.

The Mavericks coughed up a game they nearly had in the bag, and in typical Mavs fashion, it was a total team effort. In the final 6:30, as their 89-76 lead dwindled, Maverick players not named Devin Harris began hoisting jump shots rather than driving the ball to the rim – despite the fact that the Heat were in the penalty and Wade had five fouls (Wade, in fact, picked up his fifth foul with almost 11 minutes to play, meaning the Mavs wasted ample opportunities to foul him out of the game and prevent his subsequent heroics).

Guards Jerry Stackhouse and Jason Terry missed open shots from spots where they routinely hit, Dirk Nowitzki missed an 18-footer, and more importantly, he committed an offensive foul for a moving pick on a play where Terry had easily beaten his defender without help all night. Amid this breakdown, coach Avery Johnson failed to change the Mavericks’ defensive schemes as the Heat inched closer and finally took the lead. By the time Nowitzki, a 90% free throw shooter, missed the potential game-tying freebie with three seconds left, it was no big surprise. Dallas had been missing big shots for several minutes.

If the Mavericks lose this series, those six and half minutes will live forever in Dallas sports infamy.

In all likelihood, the Mavericks won’t allow that to happen.The third quarter of Game 3, in which they turned a 52-43 deficit into a 77-68 lead, suggests there’s little reason to believe that the momentum swing of the Heat’s comeback won’t be more than temporary blip in this series.

In the first half, the Heat did what every team getting outplayed in their half-court offense needs to do: they picked up the tempo. By moving the ball briskly and setting up to run their offense before Dallas could set its defense, the Heat produced their best half of the series.

However, Dallas has had problems with transition defense in the past. One of the highlight clips from their playoff run may be coach Johnson’s press conference after his team’s Game 1 loss to Phoenix in the Western Conference Finals, in which he answered every question by repeating the phrase “transition defense” with increasing volume. His team got the message; the Mavs put on an impressive display of defense in Game 2 to even that series.

After a first half in which Miami – a less athletic opponent than Phoenix – consistently beat Dallas down the floor, it would have surprised no one if those words,”transition defense,”came echoing loudly out of the Dallas locker room during halftime. Whatever Johnson said worked; the Mavericks played the third quarter with renewed focus and determination, racking up fouls against Wade and rendering Shaquille O’Neal impotent with a variety of double teams that came from different directions and prevented him from getting easy looks at the hoop.

The third quarter was also the only frame in which Dallas out-rebounded Miami. Although nobody in the Dallas lineup is reminiscent of Kevin Garnett, the Mavericks are one of the best rebounding teams in the league. During the postseason, they rank third in Rebound Rate, a stat developed by John Hollinger that measures the percentage of total rebounds a team inhales. Dallas has grabbed 54.5% of all missed shots in their games, and have been exceptional at cleaning the defensive glass, rebounding 77.8% of opponents misses.

Before Tuesday night, Dallas had been out-rebounded only once all postseason, in Game 1 of the Finals, when the Heat edged the Mavs on the boards, 45-43, a fairly insignificant margin. On Tuesday night, however, it was as if Dallas had reverted to the old soft team of a few years ago.The Heat dominated the glass 49-34, and in particular grabbed 16 offensive rebounds – nearly twice as many as the Mavericks’ postseason average.

While there is undoubtedly some skill involved in rebounding, among players of comparable size it mostly comes down to effort – a willingness to mix it up with the big bodies, absorb contact, and grab the ball. The Mavericks’ poor rebounding numbers suggest that they played Game 3 complacently. Perhaps the best evidence is that half of Miami’s offensive boards were grabbed by Udonis Haslem, who played with a left shoulder so sore he could barely lift his arm. If the Mavs couldn’t keep him from snaring 11 boards, it’s no wonder that O’Neal (11) and Wade (13) both finished with their best rebounding games of the Finals.

Yet for everything that went against them, the Mavericks lost because they failed to close out the game.At some level, it’s tempting to look at this as an organizational failing. The Mavs led Phoenix by nine points late in the fourth quarter of Game 1 of the conference finals and lost. Game 2 got closer than it needed to be because the Mavericks began eating clock with 12 minutes still left to play. And fans with good memories may recall that the Mavs blew a 27-point fourth quarter lead to the Lakers a few years ago.

Instead of a systemic failing, Tuesday’s loss is more likely to be part of the learning process of a champion. Dallas played well for only about 18 minutes on Tuesday night, which was enough that they should have won the game. Tonight, they will most likely play a full 48 with the urgency they’ve displayed during much of their postseason run. If they do, they will be another full 48 from a title.

mjohnson@nysun.com