also: cross · criss-cross block · X block
Two adjacent linemen swap assignments, one going down and one going around behind him. It gets angles on two defenders at once without anybody leaving the area.
Two adjacent linemen block each other's defender. One blocks down or across first, and the second pulls short around behind him to take the man the first one left. The paths cross, which is where the name comes from.
What it buys is two angle blocks in a place where both linemen would otherwise have been blocking straight ahead. Neither man is trying to win a square fight, and the defender who gets blocked second is being hit from a direction he cannot see coming because his read is the lineman who just left.
The timing is the whole risk. The two are running through the same small piece of ground in sequence, and a second man who goes too early gets tangled with the first, which is why a cross block is normally taught with a strict who-goes-first rule rather than as a simultaneous action.
cross, X blockdown block and fan block, combo block and double team, pullA cross block is not a pull, even though one lineman goes around another. The distinction most staffs draw is distance and destination: a cross block stays inside the two linemen involved, while a pull travels past other players to somewhere else entirely.
Reachable at youth level because the two men involved are neighbors who practice together every day, which makes the timing rule easier to hold than a full pull's.