There's an interface into this sort of play-by-play data (since 2000) at http://pro-football-reference.com/play-index/play_finder.cgi http://pro-football-refere

There's an interface into this sort of play-by-play data (since 2000) at http://pro-football-reference.com/play-index/play_finder.cgi http://pro-football-reference.com/play-index/play_finder.cgi -- lets you do queries on down/distance/position on field/score differential, all that sort of stuff.