The rabbit is player 1. Players 2, 3, 4 are the wall. Players 5 and 6 are the mids. Player 7 is the deep. There is a left (6) and right(5) mid.
The mids jobs are to protect the space between the deep and the wall.
When the rabbit is forcing a side, the mids can poach over to that side of their mark and of the field. It is players 1 and 2's job to protect the break side so that the mids don't have to worry about the players on the break side of the field (offensive player 4).
In the event the thrower chooses to throw to the break side, this is considered a risky throw and player 5 should have time to run over and knock the disc down. As soon as the rabbit calls "up" the mids should be looking for the disc and the mid closest to where the disc is going should run and try to knock the disc down (or catch it).
When the offensive team tries to
dump
and swing. It's the mids job to get to the other side of the field quickly and prevent the easy pass up the sideline.
If the offense gets the up pass.
The mids should communicate who is going to cover who and leave the thrower, keeping themselves between the thrower and the mark they are catching up to their mark.
If the offensive team sends more than one person deep, the deep will yell "help".
The mid furthest from the disc should run back to help the deep.