When Bill Belichick was deciding whether or not to go for it on fourth down in the fourth quarter of Sunday night’s 35-34 loss to the Colts, there were several reference points for him to consider, including field position, the state of the Patriots defense and the overall ability of Peyton Manning.

And what David Romer might do in this situation.

Early in his career with the Patriots, Belichick acknowledged that when it came to his overall decision-making on whether or not to go for it on fourth down, he was able to draw some information from a paper written by Romer, an economics professor at Cal-Berkeley. Entitled “It’s Fourth Down and What Does The Bellman Equation Say? A Dynamic-Programming Analysis of Football Strategy,” the 33-page paper studied a number of NFL box scores over several years — as well as mathematical, statistical and economic factors — in trying to find out when it made sense to go for it on fourth down, and when to either kick a field goal or punt it away.

Romer found that teams punted far more than they had to. His analysis included several salient points, including some that Belichick may have had in mind when he went for it on fourth-and-2 at the New England 28 late in Sunday’s game:

• Even on its own 10-yard line, a team within three yards of a first down is marginally better off, on average, going for it.

• At midfield, on average, there is an argument for going for a first down on any fourth down within five yards of a first down.

While many around the league openly scoffed at the paper — including former Giants coach Jim Fassel and ex-Steelers coach Bill Cowher (Fassel snarkily told ESPN.com, “What does the professor coach? Maybe he needs a few more classes to teach. Too much free time.”) — Belichick confessed to having read and studied Romer’s work, and had been able to put it into practice on several occasions.

“I think I understand some of the points that were made in there, and I think he has some valid points,” the coach said during training camp in 2002. “There’s sometimes an emotional aspect, and momentum, if you will to those decisions, but I’m not sure how to calculate that.

“I understand the points that he’s made. I don’t understand all the mathematical equations [of] how he got to those points, but I think that some of those are legitimate points and you just have to evaluate the situation to your team, the team you’re playing,” he added. “I see where a lot of that’s coming from.”

(The Patriots have turned to the academic world on several occasions. A few years ago, Rutgers professor Harold Sackrowitz got a call from Patriots director of football research Ernie Adams, who quizzed Sackrowitz on some work he had just done detailing football’s two-point conversion — when to go for two and when to kick the extra point. Adams sent the professor the Patriots’ “go-for-two” chart, and asked Sackrowitz to take a look. Of the 32 NFL teams, the statistician told the New York Times, only the Patriots called.)

Sunday night’s decision to go for it against the Colts was certainly in character for Belichick and the Patriots. Whether it had anything to do with Romer’s impact or not, when it comes to going for it on fourth down, the Patriots have traditionally been one of the more aggressive teams in the NFL under Belichick. (A list of some of the outside-the-box decisions by Belichick and the Patriots to go for it is available here.) In five of the last seven seasons, New England has been in the top 10 in total fourth-down attempts. This year, the Patriiots are tied for ninth in the league with 11 attempts and have converted five of them.

More often than not, they are able to convert. According to ESPN, since 2001, on fourth-and-2 or less, the Patriots had converted 76.4 percent of fourth-down plays. In that same span, the teams with the two best fourth-down conversion rates are the Colts (61.6 percent) and Patriots (60.5 percent). Interestingly, Elias also noted on Monday that since 2000, including the postseason, Bill Belichick had gone for it an astounding 16 times on fourth down against the Colts — and converted 12.

On WEEI's "The Big Show" on Monday, Belichick referenced the end of the 2006 AFC championship game — where the Patriots punted the ball away to Manning and the Colts, only to see him engineer a game-winning drive with just over a minute to go — as one of the reasons he decided to go for the first down on Sunday night.

“It came to, if we had made that play [Sunday], we would have been able to run out all or most of the clock so we didn’t need very much. We felt good about the play,” Belichick said.  "We’ve been on the other side of that one, it’s basically where we were in the AFC championship game. We’ve done it both ways and we tried to win the game on that play and it didn’t work out.”