DALLAS — Young, young, young. The Thunder proved unequivocally in Game 4 that it is nothing if not young. Until Game 5. When the Thunder proved that it is tough, tough, tough. The Thunder is more tough than young. Of course, tough isn’t enough this deep in the NBA playoffs. The Thunder lost 100-96 Wednesday night as the Dallas Mavericks won the Western Conference, sending the Thunder to an offseason of what-might-have-been and what-will-be. The Thunder just wasn’t quite good enough, again failing to close the deal despite a late lead. And the Thunder just wasn’t quite lucky enough; three loose balls went Dallas’ way in the final 80 seconds. But what an answer to that historic collapse in Oklahoma City 48 hours earlier. A team that had every reason to get dump-trucked by the Mavericks, a team that had every reason to be ground into coronation confetti, instead zealously fought. American Airlines Center brimmed with more fear than anticipation most of this night. “I knew our guys would leave everything they had on the floor,” Scotty Brooks said. “That’s how they’re wired. That’s how they’re built.” Any worry that the Game 4 meltdown — losing a 15-point lead in the final five minutes — would have lasting impact quickly was chased in the first quarter Wednesday night. Russell Westbrook set the tone with 94-foot effort, picking up Jason Kidd full court on defense and driving to the basket, under control, all game long. “We came out expecting to win today,” said Kendrick Perkins. “One thing I told our guys before we ran out there, if we’re going down, we’re going down fighting. We did that. Every guy gave 100 percent.” This kind of game was the perfect tonic to wipe out that sour Game 4. Except the ending, of course, when offensive inefficiency again felled the Thunder. In its last six possessions, after taking a 94-90 lead, the Thunder scored just two points, on Westbrook foul shots with 39 seconds left. The Thunder committed three turnovers in the final 2:24, which is where the most improvement is needed if OKC is to win the West in 2012. “The Western Conference Finals is a great learning experience for us,” said Perkins, who was reminded of a conversation with Red Auerbach years ago, when Perk was a Celtic and Red was alive. “Get the ball,” Auerbach told Perkins. “Don’t give up the ball. Every possession is key. Is key.” But this wasn’t all a Thunder meltdown. Providential hoops went the Mavericks’ way. In the final minute 80 seconds, three loose balls went Dallas’ way: • Westbrook leaped to grab Dirk Nowitzki’s missed 3-pointer but was bumped by Tyson Chandler. No call as the ball bounced to Shawn Marion, who passed to Nowitzki again. Swish. The 3-pointer gave Dallas its first lead, 95-94, since the second quarter. • After Eric Maynor missed a 3-pointer on the Thunder’s next possession, Nick Collison flew down the baseline for a hustle rebound but feared falling out of bounds and heaved the ball high toward midcourt. Dallas’ Shawn Marion speared the ball and sped to a breakaway dunk, made worse by Durant’s foul that produced a three-point play and a 98-94 Mav lead. • Finally, with Dallas up 98-96, Nowitzki missed a contested shot with 17.8 seconds left, but the scramble for the ball was won by Jason Kidd, who tipped it to Nowitzki, producing the game-clinching foul shots. “Wish we could have some of those plays back,” Collison said. “I’ll think about those plays all summer.” That’s good. That’s fuel. That’s motivation for the Thunder to make sure they return to this stage, only next time hoist the trophy. “We’re not ashamed of how we played tonight,” Brooks said. “We fought ... we gave ourselves a chance to win. “I can’t complain about anything we did. We fought for 48 minutes. We played tough for 48 minutes. We’re a heck of a basketball team.” Just not quite good enough. Not yet. Berry Tramel: Berry can be reached at (405) 760-8080 or at firstname.lastname@example.org. He can be heard Monday through Friday from 4:40-5:20 p.m. on The Sports Animal radio network, including AM-640 and FM-98.1.