The 49ers’ decision to trade a haul of draft picks for Christian McCaffrey in October naturally caught the headlines. Whilst there was plenty of debate around the merits of the move from a financial and positional value perspective, there was one thing that everyone seemed to agree on, namely that it would be exciting to see how McCaffrey would be utilised in Kyle Shanahan’s offense.
We are four games into McCaffrey’s tenure with the 49ers and the results have certainly been encouraging. They are 3-1 in that spell, with the lone loss coming against the Chiefs. In that period, they rank fifth in offensive EPA per play, having ranked 18th through the first six weeks of the season.
The most interesting result of the trade is the opportunities it has opened up with Deebo Samuel on the field. Samuel is known for his ability to both as a receiver and as a running back. With McCaffrey joining the team, they now have two true hybrid weapons and that causes no end of problems for opposing defenses.
So how has McCaffrey made such an impact? And what exactly are the 49ers doing differently on offense? For this Film Room I’m going to focus on three ways that we’ve seen the 49ers use the Samuel-McCaffrey combo – split back sets, switching roles, and (not so) heavy personnel.
The numbers
Before getting into the film itself, it is worth taking a look at some numbers. Whilst McCaffrey arrived in Week 7, it has naturally taken him some time to integrate into the offense. Deebo also missed their Week 8 game against the Rams with a hamstring injury. It has only been after their Week 9 bye that the potential the pair offer has really shone through.
In the two games since the bye, McCaffrey and Deebo have been a central part of the 49ers’ offense. They have been on the field together for 54% of the team’s offensive snaps. In those situations, the 49ers have been averaging 6.8 yards per play. Their biggest impact has been in the passing game. With the two on the field, the 49ers have gone 32 of 40 for 359 yards and three touchdowns.
It has noticeable throughout these two games just how much they are moving around the formation. This alignment versatility helps to create mismatches for Kyle Shanahan and the 49ers offense. Deebo always gave that advantage, but McCaffrey acts as a force multiplier. Defenses now have to account for two players capable of lining up anywhere and performing any task.
| Christian McCaffrey | Deebo Samuel | |
| Backfield | 66 | 12 |
| Slot | 13 | 27 |
| Wide | 5 | 56 |
Split back sets
It might sound obvious, but one of the most noticeable benefits of adding an elite running back like McCaffrey is the possibilities it opens up in the running game. By this I don’t just mean the production of their running game – it’s more than that. McCaffrey’s skillset opens up a realm of possibilities for this offense in terms of the concepts they can run to a high level.
Kyle Shanahan has earned a reputation as an “outside zone” head coach, but in reality, his running game is far more diverse, and he has been leaning far more into gap scheme concepts in recent years. With McCaffrey on the field, the 49ers now have a back who can excel at such concepts, whilst also providing what you need on traditional zone runs. It’s no coincidence that since his arrival, McCaffrey’s runs have been split almost down the middle in terms of zone runs (68) and gap runs (63).
Where things get really exciting is the concepts they can now run with McCaffrey and Samuel both in the backfield. Both are equally capable of running gap or zone runs. Both are also excellent receivers. This puts opposing defenses in a bind and pretty much ensures the 49ers are always right.
Take the following play against the Chargers as an example. The 49ers come out in 12 personnel (one back, two tight ends) and line up both McCaffrey and Samuel in the backfield. The Chargers match this with base personnel. Because Samuel is, in this instance, a de facto running back, it really is more like 22 personnel vs base. That’s an obvious advantage to the running game and one the 49ers exploit here for a five-yard gain.
As I said at the outset, it isn’t just about the running game. The 49ers have also shown that they can use split back sets to beat opponents with the passing game. This showed up several times against Arizona. The Cardinals were obviously aware of the threat the 49ers pose in rushing the ball from split back sets and set out to stop it by playing base personnel.
When this happened, the 49ers exploited it by getting all five eligible receivers out into routes. Take this play as an example. San Francisco know that they will be getting either McCaffrey or Samuel matched up on a linebacker or safety, which is a mismatch every time. Sure enough, the Cardinals drop back into zone and McCaffrey finds himself in acres of space underneath.
This next play was another one of my favourites from that game. The 49ers motion Samuel into the backfield. With Marco Wilson (#20) following him across the formation, they know they are getting man coverage. The 49ers have both McCaffrey and Samuel running choice routes from the backfield. This means they can break their routes in or out depending on the leverage of the defender. The gain here is modest, but it once again shows the multitude of options available to this offense with this personnel.
Switching roles
One of the other things that McCaffrey has allowed the 49ers to do is to switch up roles. Whilst Deebo has always been able to play as the lone back in the backfield, that’s always come with a compromise. If the 49ers want to stay in 11 or 21 personnel when running a singleback formation with Samuel, they are forced to put the running back out wide. With most running backs that isn’t going to get you much.
With McCaffrey on the field, no such limitations exist. He might be a running back by name, but he is such a talented pass catcher that he could easily be a full-time slot receiver in the NFL. This means the 49ers lose none of their offensive potency when he’s out wide and Deebo is in the backfield.
One of my favourite plays they have run from this alignment came in the third quarter against the Chargers. McCaffrey is aligned as the outside receiver on the field side of the formation, with Deebo in the backfield. At the snap McCaffrey goes in orbit motion, drawing the defense’s eyes. In reality it is just a handoff to Samuel, who takes it for a 15-yard gain.
LAC – Deebo Run
They had similar success with these alignments against the Cardinals. the play starts off looking fairly standard, with McCaffrey and Samuel aligned in a split back set. McCaffrey then motions out to the slot. How the defense responds not only to the shift in formation, but the fact that both McCaffrey and Samuel are playing from non-traditional alignments tells the offense a lot.
When Budda Baker follows McCaffrey out into the slot, it is a pretty good indicator that the Cardinals are playing some form of man, or man match coverage. With Baker giving McCaffrey a big cushion, the 49ers run a slant that is wide open. McCaffrey is able to pick up 11 yards before the Cardinals can take him down.
(Not so) Heavy personnel
The 49ers have long been known for their love of heavier personnel. Sometimes this is as simple as running two tight ends, but it will also often include a fullback. One of the big benefits of this is the diversity it brings to their running game, which has always been a key part of Kyle Shanahan’s offensive identity. It also has the added benefit of forcing defenses out of their preferred nickel and dime packages and back into base personnel.
What is interesting following the addition of McCaffrey is how Kyle Shanahan is using this heavy personnel in unconventional ways. The most obvious of these is his ability to dial up passing concepts out of heavy personnel that include all five eligible receivers getting out into their routes. This isn’t something you see from other teams in the NFL, primarily because they don’t have the versatile personnel that the 49ers can boast.
Take this play against the Cardinals for example. The 49ers come out in what would traditionally be called 21 personnel (two backs, one tight end). Kyle Juszczyk comes in motion, before settling in his natural fullback spot. At this point, everything about this formation screams that the 49ers will run the ball – wrong!
Instead they not only run a pass play, but get all five eligible receivers out into routes. The fact that they can do this is testament to the route running talent in the backfield and it clearly catches the Cardinals off-guard. Deebo finds the hole in the zones over the middle of the field and picks up a first down.
Here is another great example of how they diversify their passing attack from 21 personnel. It looks completely different to most teams running 21 personnel though. Both McCaffrey and the fullback Juszczyk are flexed out. Tight end Charlie Woerner is lined up as an outside receiver, with Deebo Samuel in the backfield. Bradon Aiyuk is the only potential pass catcher lined up in his conventional location.
The Cardinals predictably match with base personnel, meaning three linebackers and four defensive backs. Kyle Shanahan knows that this more than likely means that one of Deebo or McCaffrey will be lined up against a linebacker, and he’s right. McCaffrey beats his man on a slant and picks up 12 yards.
The next play against the Chargers perhaps best encapsulates just how versatile this 49ers offense can be. Once again, they are in 21 personnel. This time you see them do something that few other teams would even think of doing, and that is using this personnel in an empty formation. Once again, the versatility of their pass catchers shines through here.
At the snap, Deebo goes in orbit motion. You can see the impact this has on the defense, who are understandably drawn to the presence of Deebo and McCaffrey on the same side of the field. This is exactly what the 49ers want though, as it leaves Brandon Aiyuk one-on-one to the top of the screen. Jimmy Garoppolo delivers a good ball and Aiyuk picks up an easy five yards.
These are just a few of the ways that the 49ers have varied up their offense since the arrival of Christian McCaffrey. The creativity from Kyle Shanahan is truly impressive, and it feels like we are still only scratching the surface of what this offense can do. Whatever you might think of positional value, it is pretty clear that the arrival of McCaffrey has elevated this offense to a point where the 49ers look like legitimate Super Bowl contenders once again.
