Why (and how) do people do this?

[Landonio]

I've watched a lot of PvP of M25, and I've noticed that everyone seems to do this. The thing is, though, I don't know how they do it or what advantage it gives, if any. Forgive me if this is a n00bish question and I'm missing something obvious, as I don't really play PvP and haven't since Madden 11.

On offense, they somehow set their entire O-line to zone block. Their tackles will block towards the edge, their guards will block somewhat towards the edge, the center will block straight back. It's hard to explain but if you've seen it you'll know what I'm talking about. Everyone seems to do it online.

On defense, they will somehow set their entire D-line to blitz straight ahead. No angles at all. I can't seem to figure out how to do this, either, or what advantage this actually gives to the player.

Also, how do you set the CPU to run a random play in practice mode (on offense or defense)?

Any feedback would be greatly appreciated. Thanks.

[TMJOHNS18]

O-line may be spread, hit L1/RB and up I believe to spread.

D-line, hit L1/LB and down will have the line crash down, can go to each individual player and hot route a blitz and it'll bring them straight down.

Practice should have an option for random play outside of formations, don't know, haven't done practice mode in a few maddens.