Standard caveats: I am not a professional statistician or a great DEL coach (yet). If you lose because you take my advice, that is not my fault.
A study of the 3 wide receiver formations
There are three standard three-wide formations: I-formation, Pro set, and single back. Because throwing into space is generally better, and you don't want to cross zones, I think extra weak is infinitely superior to extra strong, so I'll only be studying that. I want to see how the different back setups, and the addition.
I set up a simple playbook with the five basic rushes and a simple mix of passes (each outside receiver runs one of each route except for two of the deep routes, and WR3 is always running a dump route). The pass/rush balance is set at 50%, the run middle setting is 56.8%, which should result in roughly equal amounts of each run being called. The settings are the same for every situation, with least adjustment to playcalling and most to execution.
The defense keys nothing and runs a 4-3, 2-man defense on every play, defensive line tight, 1 ILB, 1 OLB (which shouldn't matter in the proto sims).
I ran 50 sims of every playbook and copied the data into a spreadsheet to check for pass protection and all rushing results in normal situations.
I wanted to study two things: The pass protection and the rushing results. However, here is my pass protection data:
Protection
I Formation 4.16
Pro Set 4.16
Single Back 4.18
So either the setup makes no difference or pass protection data doesn't include backs and ends pitching in. I'm not sure which, but probably latter.
But with the rushing data, we got some useful stuff. You'd expect the I formation to be best at rushing up the middle, the pro set to be slightly behind overall rushing but better at strong side than the I, and the single back to be the worst rushing formation, except for perhaps on strong sweeps.
First, average blocking:
Average blocking by hole
SSWP SIT MID WIT WSWP
I Formation 2.82 4.53 4.47 4.45 2.8
Pro Set 2.91 4.44 4.42 4.42 2.68
Single Back 3.52 4.36 4.18 4.26 2.64
Not a real significant difference anywhere, except that the end helping out in line blocking gives a boost to the strong sweep of about .5 blocking points.That is a fairly significant difference.
Rushing results by hole:
Strong sweep results
Avg. gain No gain or loss/game 10+ gains/game
I formation 5.26 .78 .4
Pro Set 5.81 .88 .74
Single Back 6.08 .74 .78
The single back, predictably, does much better at the strong sweep, and the pro set gets a boost because the lead blocking fullback is already on the strong side, giving him a better chance of successfully hitting a lead block. Remember: the sim makes a differentiation between line blocking (where the TE is spending a portion of his time, but the backs do nothing) and lead blocking (where the backs are spending all their time and the TE is only occasionally involved). They also involve different skill sets. It is possible that against a 4-3, instead of a 4-2, lead blocking a LB becomes more important and the Single back loses some effectiveness.
Strong IT results
Avg. gain No gain or loss/game 10+ gains/game
I formation 5.33 1.18 .4
Pro Set 5.57 1.32 .74
Single Back 4.31 1.74 .78
As we move inside, single back loses its effectiveness because the back is essentially on his own against two linebackers. The Pro Sets advantage may be statistical noise, or it may be the effect of the fullback being closer to the strong side.
Middle results
Avg. gain No gain or loss/game 10+ gains/game
I formation 5.15 1.26 1.34
Pro Set 5.37 1.26 1.56
Single Back 4.31 1.4 .92
Same as before, though you'd expect the I formation to do better. Proably just statistical noise. Notice how single back gets whomped, though.
Weak IT results
Avg. gain No gain or loss/game 10+ gains/game
I formation 5.33 1.26 1.26
Pro Set 4.2 1.56 .66
Single Back 4.02 1.52 .86
As we move to the weak side, the single back still gets whomped and the pro set starts to fall behind too. The fullback has a hard time coming from the strong side to lead block for a tailback running weak.
Weak Sweep results
Avg. gain No gain or loss/game 10+ gains/game
I formation 4.73 .96 .46
Pro Set 3.09 .8 .14
Single Back 3.9 .76 .24
Predictably, the I formation does much better here. I'm not quite sure why the Pro Set does so much worse than single back. Could just be statistical noise, because the weak side is consitently the least run through hole, by a long shot, less than 3 times per game on average, so those numbers will have the highest variability.
So what have we learned? Pretty much the obvious, except that it makes a pretty big difference which holes you run through. You don't want to run exclusively through one or two holes, but you do want to run mostly toward your strengths. In I formation, that is up the middle and toward the weak side. In Pro Set, that is the two strong side runs and the middle run. In the single back, that is the strong sweep.