OKLAHOMA CITY -- Here's the measure of where the Oklahoma City Thunder were and where they're going: They've become so good at the big things that we can now dissect how bad they are at the little things. Given that most of their key players should still be in college, this isn't exactly shocking. But Oklahoma City's inability to make key plays down the stretch bit them again in Game 5, a season-ending 100-96 loss to the Dallas Mavericks. For the second straight game, the Thunder blew a late lead, this time crumbling under Dallas' 14-4 closing run that featured yet another back-breaking shot from Dirk Nowitzki. This one sends the Thunder into the offseason pondering both how far they've come and how much farther they have to go. "A couple times this postseason we lost our composure," Thunder center Kendrick Perkins said. "It's nothing about our talent, it's nothing about our togetherness." Fittingly, it was the little things that did them in at the end. Like a loose-ball situation in which Russell Westbrook may or may not have been fouled by Tyson Chandler, leading to Nowitzki's go-ahead 3-pointer. "I don't know what to tell you," said Westbrook, who clearly wanted to avoid a fine. Like backup point guard Eric Maynor waving off a screen and then taking perhaps the most important shot of the season with 55.9 seconds left and the Thunder trailing by a point. "Had a chance to make a basket and missed it," Maynor said. "It happens." Like Thunder coach Scott Brooks going with a small lineup the entire fourth quarter, leaving Serge Ibaka on the bench and Maynor on the floor. His only substitution was putting in Daequan Cook with 13 seconds left. "I knew that in order to beat this team we had to keep moving their feet and we put as much quickness on the floor as possible," Brooks said. "We were looking to get opportunities to use our speed and use our quickness to get around the rim and get some fouls." It worked against Dallas' bench, but once the varsity unit came back in it was a different story. After Dallas went big by putting in Chandler at the six-minute mark, the Thunder were outscored 17-6 the rest of the way. Of course, there were the usual shortcomings we've seen throughout the playoffs -- Kevin Durant struggling to get open, Russell Westbrook struggling to make jumpers, a lack of offensive complexity, and the Thunder's three other starters struggling to do anything of significance. So they have weaknesses. Glaring, obvious weaknesses. But the Thunder are going to get better. And Perkins hit the nail on the head: That they made it this far with so little experience and so many flaws in the little things speaks volumes about their talent, toughness and togetherness. It wasn't always pretty to watch, but they were amazingly effective. And as bad as they looked in the past two fourth quarters, one should also remember that they were quite good in those situations during the regular season. Oklahoma City was 8-2 in overtimes and 18-11 in games decided by five points or less. Just a few weeks earlier, in Game 5 against Denver, they did almost the exact same thing to the Nuggets that the Mavs did to them Wednesday. "We closed games all year," Maynor said. "We just fell short." So they'll move forward and try again next season, a year older and a year wiser. And yes, this will be the group doing it. Sorry to disappoint the knee-jerkers in the audience, but they're not trading Westbrook, they're not firing Brooks and they're not going to raffle off Perkins. All those guys are going to be better. Brooks is in his second full season as an NBA head coach and is still growing into the gig. And with a roster this green, he has often had to keep things simpler than perhaps he'd prefer. And Perkins is battling back from a knee injury and should be much more mobile by this fall (or whenever they're playing games again), when he can be the tough, physical center that the Thunder envisioned at the time he was acquired. And Westbrook? He's here to stay. And frankly, the Thunder have been puzzled by the spotlight on his shortcomings. "It kind of baffles me," Durant said, "that people just start to criticize him because he's playing like that now. That's how he's been playing the whole season." Perkins went so far to say that Westbrook has taken a lot more heat than his former teammate, Rajon Rondo, did in Boston prior to the Celtics winning a championship. "One thing I learned," Perkins said, "is I don't watch ESPN, I don't read the papers, I don't do none of that. I don't even talk basketball with my own wife. Seriously. Because it could break up a locker room, it could break a team. I think Russell handled everything well. One thing about Russell, he's great with adversity. He always kept his head high, he never showed any sign of weakness." "Russell's [been treated] worse than Rondo. Rondo's lasted a little bit, but Russell lasted for the whole playoffs, no matter if he played good or bad, he was getting criticized about something." That may be the biggest takeaway from the Thunder's playoff run. As Nick Collison noted, the added scrutiny is going to help them in the long run, especially if they can stay together through it. The unequivocal support for Westbrook was a very good sign in that direction. When the dejection over the blown leads in Games 4 and 5 wears off, one realizes the big picture remains blindingly bright for Oklahoma City. Looking forward, this is the most talented team in the Western Conference. They lost to a savvier team that excelled in the exact areas where the Thunder struggled, but they've also improved by leaps and bounds in this department every season. There's no guarantee they make it back here, obviously, but you have to like their chances. And when they do, experiences like this one -- painful though it may be -- might help push them over the hump.