INDIANAPOLIS -- When NFL teams ask Mason Graham for a game film from his college career that defines him as a prospect, the Michigan man has plenty to choose from.

For the second year in a row, the Miami Dolphins and Minnesota Vikings earned top marks in the NFL Players Association's annual survey evaluating workplace environment. Overall, grades improved in the union's latest survey,

"We saw overall improvement across all 32 teams," NFLPA chief strategy officer JC Tretter said. The Falcons, who were 25th last year, moved to third after opening a new team train