What to expect from the Rams’ offense, and how the Patriots should defend it

The Los Angeles Rams had one of the most explosive offenses in the NFL in 2018. They finished No. 2 in points (32.9 per game). They scored at least 30 points in 13 of their 18 games. They had the second-most completions of 25-plus yards (40).

And they did it by being the anti-Patriots.

The Patriots are known for their variety — a multitude of personnel packages, formations, and new looks each week. At various points in the game, they use all four receivers, all three running backs, both tight ends, and their fullback.

The Rams are the opposite. They ran the same personnel package on a whopping 90.1 percent of offensive plays: three receivers, one tight end, one running back. And it’s the same three receivers, and, when healthy, the same running back. In most games, the Rams have eight or nine players who don’t come off the field.

No team used the “11” personnel — one running back, one tight end, and three receivers — more than the Rams. The league average was 65 percent.

“Well, they switch things up a lot. They just do it with the same players,” Patriots coach Bill Belichick said. “That’s what makes them so good, is everybody can do everything.”

By not substituting much, the Rams can get to the line of scrimmage quickly, dictate the pace of the game, and force the defense to declare its intentions. It also simplifies the game for quarterback Jared Goff, now in his third year, and allows coach Sean McVay to communicate with Goff at the line of scrimmage until the helmet radio turns off at 15 seconds.

The Rams operate like a junk-ball pitcher, constantly keeping the defense off-balance with varied snap counts and frequent audibles.

“The one advantage that we do have offensively is we decide when the ball is snapped, and we try to use that as a weapon and as a tool to try to keep people off-balance,” McVay said.

Let’s take a look at what the Rams do on offense, and how the Patriots might try to stop them:

Coordinator: Sean McVay (third season).

Key stats: Second in points (32.9 ppg), second in total offense (421 ypg), third in rushing (139.4 ypg), fifth in passing (281.7 ypg), fifth on third-down conversions (45 percent), 18th in the red zone (57.5 TD percentage).

Key personnel: QB Jared Goff, RB Todd Gurley, RB C.J. Anderson, WR Brandin Cooks, WR Robert Woods, WR Josh Reynolds, TE Gerald Everett, TE Tyler Higbee.

Injury/lineup notes: The Rams’ only significant injury is to WR Cooper Kupp, who has been on injured reserve since Week 8 and has been replaced by Reynolds. Gurley is dealing with a knee injury and has lost some playing time to Anderson.

What to expect: The Rams’ West Coast offense-based scheme is quite similar to what the Patriots faced against the Atlanta Falcons two years ago in the Super Bowl. McVay cut his coaching teeth in Washington under Kyle Shanahan, who was the Falcons offensive coordinator in Super Bowl LI. That offense gashed the Patriots for 2½ quarters before running out of gas.

The Rams offense isn’t necessarily complicated. It mostly entails a lot of variations of the same few plays and formations. But it is quite effective, because the Rams disguise so well whether the play is a run or a pass. Everything looks the same before the snap.

As mentioned, the Rams don’t substitute much. They use only a single running back, never a fullback or a tight end, in the backfield. Cooks and Woods never come off the field. The other two skill spots are split among Reynolds, the new No. 3 receiver, and the two tight ends, Everett and Higbee, who are proficient blockers and receivers.

One key aspect of this offense is having tight ends and receivers who can block well, reducing the need to substitute players.

You’ll see one formation from the Rams for much of the night: a bunch formation with three receivers on one side and a single receiver on the other.

Sometimes the bunch formation is tight.

Sometimes it is flexed out wide.

And they often bring a receiver in motion before the snap.

The point is that since the Rams use the same personnel, formations, and motion, there are no tells. On one play, the receiver in motion could take a handoff on an end-around.

On another, he could catch a quick swing pass.

On another, the receiver is simply a decoy to soften up the middle of the defense for Gurley, who has the speed and power to rip off a big run at any time.

The bunch formations allow the Rams to create space for their receivers at the line of scrimmage with legal pick plays. There’s a lot of traffic for defenders to wade through, and it can often lead to an easy, quick throw from Goff to a receiver over the middle or into the flat.

And the Rams run a ton of play-action passes. Their passing game really revolves around feeding Gurley (or Anderson) early and often, then hitting big strikes with play-action.

The Rams called the eighth-most rushing plays in the NFL this year, and were only 14th in pass attempts. Gurley was a workhorse, leading the NFL with 21 rushing touchdowns and finishing second with 130.8 total yards per game.

Anderson has been just as effective spelling Gurley as he deals with his knee injury, rushing for at least 123 yards in three of the Rams’ last four games. The Rams are 9-0 when they have a 100-yard rusher.

To execute the play-action, Goff will be under center for a good portion of the game, not in shotgun. Goff was under center for 37.3 percent of passes this year, the highest rate of any quarterback. The Rams still do plenty of shotgun formations, but they ran the ball a league-low 27 times out of the shotgun.

The Rams are devastating with their play-action passes. One of their favorites is a rollout to the right for Goff, which cuts off half the field and gives him an easy high/medium/low read with his three receivers right in front of him.

Another favorite is a two-man route with Cooks and Woods running 20-yard digs over the middle.

The play-action helps keep the pass rush at bay; the Rams allowed just 33 sacks, tied for eighth-fewest in the league. And it helps the Rams create chunk plays. They averaged just 7.51 plays per scoring drive, sixth-fewest in the NFL. Goff’s 40 completions of 25-plus yards were second-most. He also had a league-high 48.2 completion percentage on passes that traveled 21-plus yards in the air.

Goff threw 12 interceptions, but a lot of them were fluky, such as the one Sunday against the Saints that bounced off Gurley’s hands. McVay’s scheme generally produces a lot of time for Goff in the pocket, and wide-open throwing lanes.

The Patriots know all about Cooks, of course, and know that he’s one of the better deep receivers in the league, but he doesn’t have much physicality or run-after-catch ability (64th among wide receivers in yards after catch this year). Woods is an excellent possession receiver, and fearless over the middle. Their stats were amazingly similar: 86 catches, 1,219 yards, and 6 TDs for Woods, and 80 catches, 1,204 yards, 5 TDs for Cooks.

Former Patriot Brandin Cooks was a key weapon for the Rams this season.marcio jose sanchez/AP

Everett and Higbee are both good for three or four catches per game, usually in the flat, but they are dangerous deep targets on the “out-and-up” route. Most of Gurley’s catches are screens and check-downs, but the Rams occasionally will split him out wide into the bunch formation, and throw him a quick hitch or drag over the middle.

The Rams offensive line is one of the best in the NFL, though some of that is due to their effective use of play-action passing. Their zone blocking scheme created a 4.9-yard rushing average, third-best in the NFL. Their 33 sacks allowed were eighth-fewest. And the Rams committed just 10 holding penalties, third-fewest.

How the Patriots should defend: The Rams don’t make many mistakes. But when they do, I noticed a few similarities.

First off, Goff struggles a bit more against zone coverage. His interceptions against the Eagles, Bears, Lions, and in the first Saints game all came against zone coverage. In Week 9, Goff never saw Saints linebacker Alex Anzalone dropping into the middle of the field, and Anzalone snatched a rocket over the middle.

The Saints mostly played zone in the NFC Championship game, and they dropped their linebackers into the deep middle portion of the field to defend against the play-action passes to Cooks and Wood.

The Saints held the Rams to 26 points, their fourth-fewest of the season.

In the divisional round, the Cowboys generated a decent amount of pressure with their blitz. And there are opportunities for linebackers to shoot through the gaps and make big plays in the backfield, if they guess the play correctly.

The Patriots played almost strictly man-to-man coverage against the Chiefs, but the Rams offense is designed to eat man-to-man coverage for breakfast, with all of the presnap motion, bunch formations, and play-action. So I would expect a heavy dose of zone from the Patriots.

Since the Rams like to get to the ball and quick-snap, zone coverage can eliminate a lot of presnap confusion for the defense. And zone coverage can help eliminate the deep ball to Cooks.

But variety will be key for the Patriots defense. They need to switch up their zone coverage throughout the game, as they have been doing the last several weeks. The Patriots should blitz Goff heavily, and continue to disguise their pass rush before the snap with their “amoeba” front. Goff, like most young quarterbacks, can be goaded into mistakes.

Devin McCourty and Patrick Chung will be important Swiss Army knives and should defend the hash marks to take away the deep-middle throws. And the Patriots need linebackers Kyle Van Noy and Dont’a Hightower to be on point. They will be on the hot seat all game, and need to be patient and disciplined, so as not to bite too hard on the play-action fakes.

Because one false step, or one misread, and the Rams will make you pay in a hurry.

Ben Volin can be reached at ben.volin@globe.com. Follow him on Twitter @BenVolin