For the Patriots, Shanahan’s preferred style is a bad matchup, point-blank. The 49ers run most of their offense out of either 21 or 12 personnel with a fullback (Juszczyk) or an extra tight end.
San Francisco runs the football out of 21 or 12 groupings on 88 percent of their plays, and 41 percent of those runs are Shanahan’s outside zone, the basis of his offense.
New England is primarily a nickel or dime defense, playing with five or more defensive backs on every down, and surrenders 5.2 yards per rush on outside zone carries through five games, per PFF.
In other words, the Niners are a big, physical ground and play-action passing attack against a small Patriots defense.
Shanahan then incorporates play-action sequences off outside zone and quick-hitting shotgun passing designed to create YAC chances for Kittle, Samuel, and company.
The Pats must prepare for everything and stop the run with lighter personnel. As we saw last postseason, Shanahan is not afraid to pound the rock if you can’t stop them.