​In a dwindling gym that was about a quarter-filled, we’ve reached the point of Summer League when only the true hoop sickos tune in. All of the top prospects are beginning to sit out. Teams have seen enough of their prized draft picks. Same happened here for both sides as the top three attractions chilled on the bench.The Oklahoma City Thunder fell in a 97-87 Summer League loss to the Dallas Mavericks. They remain winless through seven tries in the July extravaganza at both Utah and Las Vegas.AdvertisementAdvertisementAdvertisementAbout a half-hour before tip-off, the Thunder ruled out Aday Mara and Bennett Stirtz for their final two Summer League games. The two top-16 picks have shown enough to get sent on vacation early. Meanwhile, the Mavericks played it extra safe with Morez Johnson Jr.’s calf injury.Without those household names, this turned into a pseudo-G League game. Brooks Barnhizer drove to the rim for a wide-open dunk. Josh Dix then knocked down an outside jumper. Those are the two guys to watch if you’re OKC for the rest of the way. Both are two-way players.The Thunder had their best start in a Summer League game. The ball zipped around to find their outside shooters. They were in a 24-20 deficit after the first quarter. The second frame was much of the same. Both sides put up points in a flurry. In one stretch, the Mavericks had a 3-point barrage. They couldn’t miss from deep.Darin Green Jr. swished in an outside jumper. At one point, Kaodirichi Akobundu-Ehiogu caught three alley-oops within one minute. In the end, both teams tallied 25 points in the second frame. Anthony Pritchard’s full-court heave kissed the bottom of the Jumbotron. The Thunder entered halftime in a 49-45 hole.AdvertisementAdvertisementAdvertisementA pretty competitive game — even if the stakes were lower than usual in this environment thanks to who was out. Alas, the Thunder started the second half in the worst way possible. They were on the wrong side of a 20-2 run. Dallas had a group effort as several players made outside jumpers.Not even four minutes into the second half, the Thunder were suddenly in a 69-47 deficit. Talk about things escalating. Guys like John Poulakidas and Vsevolod Ishchenko sprinkled in 3-pointers. And Sergio De Larrea looked like John Stockton as he racked up the assist numbers. The Mavericks’ athleticism and speed jumped off the page.After being blitzed, the Thunder settled things down. They scored 18 points in the third quarter to salvage things. They were in a 77-63 deficit through three frames. Not a bad spot to be at, all things considered. To make things a little interesting, OKC started the final frame on a 13-5 run. Dix’s outside jumper made it an 83-76 game with over five minutes to go. Uh oh.Suddenly, the Mavericks’ hot outside shooting cooled off. And the Thunder enjoyed things evening out. Barnhizer pushed the pace in transition as OKC’s primary ball-handler. Alas, the closest they’d get was within single-digit points. They