What impact, if any, does the RB's positioning affect the run fit?

[u/zawwery]

I see all the time at both levels, a RB could flip sides or go from pistol to left or right of the Qb or even have another back enter the backfield to form split backs. It seems that the majority of the time the defensive front is "static" or "locked" or whatever nomenclature you use and don't move with the back. It seems at most, one of the backers point to the RB but I don't know if he's giving a specific call or just making sure the other backer is on the same page.

I guess a more accurate version of my question is what happens (if anything) to the LB's run fit responsibilities in a static front when the RB changes his positioning?

[u/miketangoalpha]

If the front doesn’t shift the responsibility of the backers would likely not change. However the “fill” responsibility may as the change from a single to 2 back backfield may change the pass defense scheme and now you have a free backer.

It may also affect tendency depending on the scouting you may not have “moved” the front but they may now be slanting in a new direction which may change responsibilities. It’s honestly difficult to tell without knowing the team and the play caller

[u/Untoastedtoast11 → u/miketangoalpha]

2 back can also create an extra gap (same will pulling lineman) so it does affect LB flow

[u/djm2346]

The short answer is the RB position the majority of the time doesnt have a huge impact. The long answer is this is a very complicated question with a very complicated answer depending on what run schemes the offense runs, how the defense calls the strength, and who the defense is putting in the run front

[u/grizzfan → u/djm2346]

Yea, I was trying to think of a short handed way to explain it all but there really isn’t. It depends a lot on the type of fits or system you run, the game plan, the keys you’re making calls off of, coverages, etc. The RB alignment at the same time could have no impact at all.

[u/Kainlow]

It would only the line if the RB motioned out or aligned into a bunch/trips.
If they are within the pocket LB’s become aware of wildcat. If it’s an RPO offense they are aware anyway

[u/WinnyRoo]

The strength of the formation predicates the run fits more than where the RB lines up. If TE's or OL shift to change/add gaps then fits would be adjusted. The RB moving from one side to the other doesn't re change gap responsibilities for the DL and LB's. 

[u/Income-Wild]

It changes things a lot mainly in 2 high and potentially targeted pressures if you are setting things by back location

[u/Ok-Face-8267]

Specific alignments like where the HB is set, whether a TE is on or off the line, how close the Flanker is, etc., are mostly just affecting the concepts to expect. The actual mechanics of the run fit is more of a post-snap key read type of deal like the backfield flow, the G-T-HB triangle, the footwork of the HB, etc. Your defensive structure is mostly what you’re fitting from (7- or 8-man spacing, front mechanics, your primary forces) and dictating how to play blocks, whether to box it or spill it, etc.

[u/Good-Reference-5489]

A lot of good comments here, only I’d add is that usually, a Back flipping sides or aignment might change which LB has him in pass coverage, or it might give a “tell” to what play the Offense will run

[u/BarnacleFun1814]

It matters to the run force from the secondary quite a bit I think.

The offense has way, way more RPO/option stuff to the side of the RB in the gun.

[u/jasondavis52]

Some examples:
Power out of pistol is more downhill so you get less LB flow as the back isn’t moving across their face but it also doesn’t initiate an outside step from contain player as initial movement is downhill. Running it out of side car changes all of that. Adding the kickout back into a 2 back set changes his path to kick so depending on how the contain player plays could give better leverage.

Outside zone causes the QB to face play side removing the read option but adds in RPO to run side if team is RPO. Personally I prefer outside zone from sidecar as Read Option/RPO is there. It changes the back’s vision of the hole depending on how line and backers play either could be better.

Some plays are hard/impossible to run out of certain alignments so the complimentary play could drive alignment as well.