1 x 1 (3-back) “Full House”
2 x 1 (2-back) “Regular”
2 x 2 (1-back) “Doubles”
3 x 1 (1-back) “Trips”
3 x 2 (empty) “Trips Empty”
4 x 1 (empty) “Quads”
Each of these six types can be further broken down to take into consideration where the tight end(s) are aligned, specifically if the passing strength is to or away from the tight end, the backfield alignment, who is and isn’t aligned on or off the ball, and variations on splits. Not to mention, we haven’t touched on the unbalanced line and unconventional offensive line splits. You could also have players out of their conventional positions, like someone besides the quarterback taking the snap. It makes for a big subject and as always there is a wide variety of different practices and terminology in use. It will continually be said on this site, the terminology used here isn’t set in stone, it’s the underlying concept that is the real subject. The terminology can be improved upon. I will borrow terminology from different sources as I see fit in order to describe the concept being presented.
Also, when talking about offensive formations it’s important to take into consideration the perspective, whether it’s offensive or defensive. Offensively you want to have a way to make the names for formations and alignments easy to remember so they can be constructed on the field, whereas defensively you are deconstructing the offensive formation as it presents itself on the field to determine how the defensive front and coverage should be set.
I’m still working on the Offensive Formations page, trying to find a way to present all of this information in an organized, readable way. I’ve made separate pages to cover the basics for those coming to the site without the prerequisite knowledge. If you have any suggestions I’d be interested.