In football, coaches like to make things more complicated and half the time I believe it's to seem 'smarter' than the marks in the bar that watch on TV and play fantasy football, and the other half is that with technology getting coaches film on the field you have to change your blocking schemes even when running the same play.
First I will cover a few of the different blocks and I believe it's easiest to display in two plays I have discussed in the fanposts sections of SOTU- power and inside zone. With power, you'll see the scoop or gap hinge (basically the same block), a down block, a skip-pull, kick, and two (what I call) "at" blocks. The only run blocking step we will discuss via power that we discuss in this post is a flat or trap pull.
As you can see in the diagram above, The Y takes a reach step (aiming point of his eyes is the outside shoulder of the End across from him) and arc blocks (save for another day) the SAM (S). The Left Tackle and Left Guard both take "at" steps and combo block the 3-technique (T) and whichever OL can, will block a linebacker at the second level. The Center down blocks the 1-technique (N). The "backside" Right Guard skip-pulls and wraps through the B-gap to block the first man that shows. The RT (backside) will gap-hinge (TE to bottom of screen in the GIF shows a great gap-hinge) or scoop blocks the b-gap to insure a blitzing LB or squeezing DE can't get to the inside gap. The FB (F) will "kick" block the DE on the left side and run him to the sideline so the running back (T) can run underneath him and behind the wrap.
Another pull step use is the flat pull or trap pull. Some guys use a flat pull on power but I prefer the skip pull (as does Coach Richt) because it's faster and keeps the Guard's eyes and hips pointing forward towards his opponent which is his target. You can see above how fluid the guard is on the skip-pull and how easy it is for him to find someone to block. However, if you're running Guard Trap to the 5 or 3 technique (DE or DT) many coaches will use a trap pull step or a straight line pull because your opponent/target will show to your eyes easier since he's down the line.
In the diagram you see down blocks, at blocks (combo'ing as well) and a flat pull. This is a Jet motion, fake sweep, RB Trap play with double slant RPO.
In the GIF above, the playside Guard and Tackle at block and combo the DT, the Center down blocks the NT, the backside guard skip-pulls to trap the 5-tech and the backside OT "through blocks" the DE which means he just rips underneath him to avoid him and get to the LB and the 2nd level.
You can also watch the video below for chalk-talk and cut-ups of power and trap and the different blocks of each.
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