One of the common refrains heard around the NFL in recent years is that the fullback position is on the verge of becoming extinct.

Here in New England was no exception. In 2011, for example, the Patriots didn't carry a pure fullback on their roster as the plan was to build around a two-tight end attack.

The Patriots haven't regularly featured the fullback position since Heath Evans' heyday. Al Messerschmidt/Getty Images

Over the years, it's been Sam Gash ... Marc Edwards ... Heath Evans and then a big gaping hole. Sometimes the Patriots have used a tight end in that role (Michael Hoomanawanui last year). Other times, it has been an offensive lineman.

But could the pure fullback be on the verge of making a comeback with the Patriots?

That was one question that came to mind after watching hard-nosed James Develin play some meaningful first-unit snaps in the team's past two preseason games, as the Patriots worked on their two-back sets.

Then you consider that if the Patriots are going to be without tight end Rob Gronkowski early in the season, maybe they're looking for different ways to make up for his strong blocking presence in the running game.

And there was also 2012, when the Patriots brought three fullbacks to training camp -- Spencer Larsen, Tony Fiammetta and Eric Kettani -- which seemed to reflect some desire to re-introduce the position into the attack. It didn't work out, but the intent was there.

So the topic was broached with Bill Belichick on Friday.

And boy, did he take the football and run with it.

The question was on the difference between a personnel grouping of "12" personnel (1 back, 2 tight ends) and "21" personnel (2 backs, 1 tight end).

We'll step out of the way and let Belichick take over:

James Develin could be in line to make the roster if Bill Belichick wants to feature a fullback on offense. AP Photo

"Fundamentally, when you have one back in the backfield and you have four on-the-line receivers, that gives you an ability to get into the defense potentially with four people. Or even if it’s three of them, sometimes the defense isn’t sure which three of them it is. One tight end could be in it and the other guy could be in protection, that type of thing. I think you’re able to attack the defense from the line of scrimmage a little bit quicker and with a little less predictability, depending on who those players are, of course. That's certainly a factor.

"But as far as your running gaps, I mean, you can put more width at the formation by having a [second tight end] on the line, whether it’s four on one side and two on the other side of the center or three and three. You just have a wider front, which there are some advantages to that.

"By having [a fullback] in the backfield, you can create that same four-man surface or three-man surface after the snap so the defense doesn’t know where the four-man surface or three-man surface is. The fullback has to -- he can build that from the backfield. And then there are also, let’s say, a greater variety of blocking schemes with the fullback in the backfield because he can block different guys and come from different angles. He's not always behind the quarterback. He could be offset one way or the other and create different blocking schemes and angles that it’s harder to get from the line of scrimmage.

"Also, depending on who your tight end is, it can be a little bit easier to pass protect seven men because two of them are in the backfield instead of us having one in the backfield. And then when you start running guys up the middle in the gaps and things like that. I think fundamentally it’s a little easier to pick them up when you a have a guy in the backfield that can step up and block him from the fullback position as opposed to a tight end in the line of scrimmage who probably isn’t going to be able to loop back in and get him, so the line is probably all going to have to gap down or not gap down if the guy drops out and all that.

"It just creates a different ... it creates some advantages, I think, and it also creates some things you have to deal with. You just have to decide how you want to deal with them.

"Obviously when you have a guy in the backfield, it’s harder to get those two receivers vertically into the defense in the passing game. They’re usually running shorter routes to the flat or checking over the ball or those kind of things, short crossing routes -- versus having that fourth receiver on the line of scrimmage who can run some downfield routes, again depending on who the individual person is. The skill definitely changes what you can do with that guy.

"So, I mean, I think those are the things that come into play. Some teams are very settled in one type of offense or another, so all of their plays and their rules or their adjustments come from that particular set. And other teams use multiple looks to, say, run the same plays or the same concepts to try to give the defense a different look. It’s harder for them to zero in on what they’re doing. But they’re able to do similar things from different personnel groups or different formations. That's a long answer to a really short question, but hopefully that helps a little bit."

Sure does. Thanks much.

It only piques the interest that much more on if the pure fullback might be making a comeback in New England.