Oklahoma City could not find its mark from beyond the arc.  The Thunder are officially now in a do-or-die situation after falling to the Spurs 118-91 in Game 6 on Thursday night. The series is now all tied up 3-3, and both teams will meet for the last time this season on Saturday night in Oklahoma City.  The Thunder had a chance to finish off the series on the road in Game 6, but were completely run out of the gym from the start of the game. OKC never led in this bout and ultimately looked outmatched as the contest continued to stretch on.  There are a lot of things that the Thunder need to improve on from this loss, and one thing in particular is their shooting from beyond the arc.  The Thunder couldn’t seem to find their stride from deep, as the team only shot 25% from three-point land.…