Just three seasons after being separated by just three points in Super Bowl XXXIX, the gap between the Patriots and Eagles has widened to historic proportions: Philly is a 23?-point underdog. That is the largest point spread for an NFL game that does not involve an expansion team, according to odds-making experts in Las Vegas. On Dec. 5, 1976, the expansion Tampa Bay Buccaneers were 24-point underdogs to the defending Super Bowl champion Pittsburgh Steelers. The Steelers covered easily, winning 42-0. "Nowadays, you don't see too many spreads over 16 or 17 points," said Sean Van Patten, an oddsmaker at Sports Consultants in Las Vegas. "That's because most teams take their starters out in the fourth quarter of a lopsided game. The Patriots don't. I call this phenomenon The [Bill] Belichick Factor."