The highly publicized three-network simulcast of the New England Patriots-New York Giants NFL contest last weekend (Dec. 29) that gave the Pats the league’s first undefeated season in decades gleaned the largest TV audience of any regular season game in a dozen years. All three networks—CBS, NBC and host NFL Network)—provided the game in HD, probably also producing the largest HD audience ever for a regular NFL game.

Although an estimated overall audience of 34.5 million saw the contest, according to Nielsen, it’s unknown how many households (and sports bars, etc.) actually watched the NFL Network’s HD feed in high definition. It was the first NFL game aired simultaneously by three networks, and the first to be carried by more than one network since the very first Super Bowl more than 40 years ago, according to The Hollywood Reporter.

The unusual last-minute carriage agreement was the result of a dispute (and as it turned out, a shrewd PR move by the NFL) between the league-owned NFL Network, which is a relatively new channel carried by more than 240 cable and DBS outlets—but notably not Comcast or Cox Cable. Thus, more than two-thirds of the nation cannot yet receive the channel (HD Notebook, Dec. 27, 2007).

Meanwhile, the NFL Network did not squander the opportunity with its newly found (and one-time only) wider audience to heavily promote itself throughout the broadcast and obliquely convey the message that it’s in a fierce carriage dispute with some major cable operators.