For the selection process....first they screen the applications..like look for TOEFL score...is it above the university Average...then the GRE score...especially the Quants score if you are an Engineering student...Then they do consider ur acads (Backlogs matter too)....sometimes backlogs don't hurt if you have an explanation for it...like u could mention about it in your SOP. However...sometimes people don't care about backlogs..like I had a friend from IIT who had one backlog but made it to PhD with aid. If the backlog is a single sore point in your profile...then I guess its fine...it wont hurt...
The UG percentage would be used by ur dept to short list candidates for their courses...these are secondary screening...and are done by the department...like if you have some papers this is where it owuld matter...also if you have a good reco..it matters here...so..thats the way it is....please get back to me if you have any doubts.
Shravan MS - Computational Engineering, UAB (6 months)