Here is an example of post snap movement. The play is zone left.
As you can see every player has stepped to the play side, and we have followed our covered/uncovered principles. 58 has worked to the knee of the next down defender, as he was an uncovered player. His next thought, as the defender did not crash his gap is to climb.
We define the climb as working in the cylinder (here the gap area between the offensive tackle and the center.) Others define it as a track.
This is another example of a zone left play. Here the guard did not step all the way down to the knee, instead climbing to fast. When the defender crashed the playside tackle had no help, so he got beat. This is the area that needs the most emphasis...FAT GUYS FIRST; Then climb to the Big Uglies. The reason for this is the onus is on the backs to "DELIVER" the linebackers to the lineman.
This is also a good example of how defenses slant different ways, and that if we follow our frameworks it doesn't matter.
More to come...