FOXBORO -- Bill Belichick may have created a monster.

Not with his roster or his schemes. But his comments to WEEI earlier this week when he invoked the three letters had media heads spinning in the buildup to Super Bowl LII: RPO.

Asked about the changes to the Chiefs offense since the last meeting between New England and Kansas City in last year's season-opener, Belichick highlighted the run-pass option plays coach Andy Reid has dialed up.

"Offensively, they've changed a lot because of the number of RPOs they run," Belichick said the Ordway, Merloni and Fauria show. "They run probably 10 RPOs a game. Maybe more that. They run a lot. That's a new part of the offense.

"We played them opening day, and then we got ready for them at the end of the season last year . . . But they didn't have the RPO system like they have it now. I'd say that's a pretty significant change. They have a number of ways to do it, but it's still a post-snap decision that the quarterback makes."

Already RPO chatter has driven the conversation surrounding the Patriots-Chiefs game for the early part of the week as though it's some new-fangled weapon whose mysteries have yet to be unlocked. The concept, though, is the same as it was when the Patriots prepped for the Eagles in Minnesota.

On the one hand, a quarterback could make his read -- sometimes it's pre-snap based on the number of defenders in the box -- and stick the football in the belly of his running back, who runs behind run-blocking offensive linemen.


On the other, the quarterback could fake a handoff, pull the football away from his back, and make a quick throw to a receiver running a quick-hitting route. The timing of the play is critical because the offensive linemen are thinking run, which means the ball has to come out quickly or else the offense will be flagged for illegal men downfield.


For the Patriots, the concern isn't that these plays are going to pick up huge chunks of yardage at a time, but they are exasperating chain-movers that the Chiefs will use on a variety of downs. On early downs in particular, RPOs can help an offense stay "on schedule" by using the run or easy rhythm-building throws to pick up yardage.

    Reid's West Coast attack still utilizes motion, catch-and-run plays and speed, but the RPO is another element that the Patriots will have to expect. As is the case with those other staples of Reid's offense, the RPO is all about getting the football to playmakers quickly and letting them go to work.

    "The RPO certainly fits into that category," Belichick said, "but [Reid has] done a great job incorporating that, probably as much as any team we’ve seen -- probably more than any team we’ve seen."

    How can the Patriots defend against it? There are a few different approaches.

    One way to challenge the RPO is by changing fronts from snap-to-snap and by disguising fronts after lining up. Mahomes will be reading the number of defenders in the box to see if the offense is outnumbered in the run game. If he sees seven defenders and only has six blockers for his back, he may be enticed to throw.

    But what if counting the number of box defenders isn't all that easy? What if he's having trouble telling the difference between a 4-3 or a five-man "bear" front, for instance?

    Changing fronts can make Mahomes' post-snap decision a little dicier as well. If Kyle Van Noy is standing up on the edge alongside Lawrence Guy, who should Mahomes be reading? Is it the linebacker? Is it the end? Who is the end? Is Van Noy rushing or is he part of the coverage equation? Those answers will impact what Mahomes does with the football and could potentially create some indecision.

    But the indecision can go both ways. As a linebacker, keeping track of where the football has gone can lead to some less-than-ideal split-second calls. Do you attack the line to help stop the run? Or do you drop into coverage to take away the pass?

    "A lot of times it's putting that one guy who has responsibilities in the run and pass game [in a bind]," Dont'a Hightower said. "That's kind of what causes the confusion in the open spot, the blind spot, in a lot of those RPO looks . . .


    "If you don't bite on [the handoff], then they're going to run the ball. That's the RPO. That's the doozy. That's the hard part about it."

    The Patriots could load up the box, enticing Mahomes into a throw, but also press at the line of scrimmage on the outside. Cover 1 -- man-to-man with a single-high safety -- could take away some of those quick-hitting RPO pass routes.

    Easier said than done against Chiefs targets, though.

    "You say that every week. 'You want to get hands on guys and mess up the timing.' It's a little different this week," Jason McCourty said, "because you talk about corners and you talk about having recovery speed at the line of scrimmage, it's not going to be perfect.
    Sometimes you gotta turn and just be able to recover. There's no recovery on Tyreek Hill.

    "If you miss at the line of scrimmage, it's good night. I think with him, you definitely want to try to disrupt the timing . . . I've got to go up there and play with good technique because if I miss this guy at the line of scrimmage, I'm going to have to holler at [Devin McCourty] or [Duron Harmon] to come help me."

    But even effective press coverage could be answered by the Chiefs by having their receivers reduce their splits, forcing Patriots defensive backs to play off. The Chiefs also like to use bunch sets at the line of scrimmage, which makes it hard to jam at the line.

    Then the cat-and-mouse game could continue, though. If the corners on the outside have to give their assignments some breathing room, the Patriots defense could leave a linebacker in the middle of the field as a "rat" to take away any slants or crossers Mahomes is hoping to complete.

    As Jerod Mayo explained it on Quick Slants this week, it might not be a bad idea for the Patriots to have two off-the-ball linebackers where one always plays the pass and one always drops back. The team will never have both in the right spot at the right time, but at least they'll have one. The linebacker dropping into the middle to play the pass, lurking in the middle of the field, might be considered a "rat."

    "I played with a guy, Brandon Spikes, he was always playing the run," Mayo said. "He was 90 percent, 'I'm going to play the run.' If you play with a guy like that, you have to declare one guy, one linebacker, 'Listen, I'm going to go hit it, no matter what.' You're going to crash, but I'm going to cover your back.

    "It's ball and chain. You have to know that linebacker is going to cover your back. And if I'm dropping back I have to know that you're causing havoc inside so that when I do take that false step back, I'm able to come recover and I knew you blew up a bunch of stuff in there."


    For as much respect as Belichick has for the RPO in Reid's system, it makes up only so much of his offense. Even if the Chiefs run 10 at Gillette Stadium on Sunday night, that will likely be a relatively small fraction of their overall number of plays.

    Still, it's enough to have the attention of the Patriots defense going into Sunday night.

    "How many times they do it is one thing," Belichick said. "The concept of it is another thing. I’d say Andy’s done a good job of building in, I don’t know, four, five, six concepts that are not just one thing. He’s got several different ways of doing it, and they’re all a little bit different for the defense, and he’s gotten some good production out of it."