When Dallas played Pittsburgh in Super Bowl X, 86 of the 87 players who were eligible to participate had never played on another team. All 43 Steelers were original Steelers. Of the 44 players on the Cowboys' roster, only Preston Pearson had played for another team (Pearson, in fact, was one of three Cowboys on that team that had never played a down of football in college; the others were Ron Howard and Percy Howard, who scored a touchdown in Super Bowl X).
Before we do, however, here's an interesting note about Giants tight end Michael Matthews as it relates to this topic. Matthews went undrafted last spring, and the two teams that expressed interest in signing him entering training camp were -- you guessed it -- the Giants and Patriots. Both teams offered the Georgia Tech product $7,500 to sign. Matthews sided with the Giants, figuring he might have a better chance to make their roster. Sure enough, he made it from the start and has been the No. 2 tight end since Jeremy Shockey went down.
How they were built
New England has 11 first-round picks -- seven originally drafted by the Patriots and four who came from other teams. The seven originals: Ty Warren, Vince Wilfork, Richard Seymour, Brandon Meriweather, Ben Watson, Logan Mankins, and Laurence Maroney. The four who came later: Kyle Brady, Randy Moss, Donte Stallworth, and Junior Seau.
Each team has three third-round picks on the roster.
Another sign that both of these teams are very good at finding talent is that they have a number of players who came from non-Div. I-A schools.
New England has seven such players: Stephen Neal (who didn't play football at all at Cal State-Bakersfield), Matt Gutierrez (Idaho State), Lonie Paxton (Sacramento State), Ray Ventrone (Villanova), and Troy Brown, Chris Hanson and Moss (Marshall, which was Div. I-AA when he played there).