Wha tis Michael's two board?
I missed this, or at least didn't have the energy to write it up at the time.
One-board is just a regular board drill, fully live, with a yard line or a string (between two tent stakes) instead of a board. You win when (a) you drive the opponent back some set distance, (b) one of your opponent's feet lands on the wrong side of the line (so either getting spun or crossing over, or (c) your opponent has something other than a foot touch the ground before you have something other than a foot touch the ground.
Two-board is two of those side by side, starting at the same time, with everyone competing to be the first to win. So it's a board drill with an extreme sense of urgency. First to win stays, first to lose is out, guy ahead at other board goes to on-deck circle, guy behind at other board is out, guy in on-deck circle comes in to face guy who was just first to win, two new guys come in and face each other.
For zone, everyone starts with both feet to one side of the line (to the left for zone right and to the right for zone left) and the first step has to put the correct foot across the line, or you're out. So everyone learns to step with the correct foot first, to get some actual movement out of it, and to get it down fast. And it ends up being a short step, since a step that's longer than necessary can really hurt you.