Sideline trap in ultimate frisbee

A sideline trap in ultimate frisbee is what a defence does when the disc is caught near a sideline: the mark stands on the middle side of the thrower so every open throw has to go along the line, the defender on the dump stays between the dump and the disc, and the downfield defenders move over to cover the line. The sideline works like an extra defender, because anything caught out of bounds is a turnover. The thrower is left with a short list of throws, all of them covered, while the stall count keeps going.

The sideline trap in ultimate frisbee

If your team forces forehand (see how to force forehand in ultimate), the trap happens on the forehand sideline without anyone changing the force. The mark already stands on the backhand side, and near the forehand sideline the backhand side is the middle of the field. What changes is that the rest of the defence has to know it is happening. The mark calls "trap" as they set up, and that call tells everyone else to shift toward the line.

The mark's job is the same as always, only with less room for error (the marking article covers the feet and the count). If the thrower gets an inside throw or an around break past the mark, the disc is in the middle of the field and most of the defence is standing on the wrong side of it. So the mark gives up the line, which is covered downfield, and takes away the middle.

The dump is the thrower's way out. A pass back to the dump, then a swing into the middle, undoes the trap in two throws. The dump's defender stays between the dump and the disc, so the pass back has to go over or around them rather than straight across.

Downfield, the defenders slide toward the line and stay a step downfield of their cutters. A cutter who goes up the line now has a defender already beside and ahead of them, and a cutter who goes into the middle is running away from a thrower who cannot throw there.

The trap does not always end in a turnover. If the offence completes the dump and swing, the trap is over and the defence goes back to its normal force. On the backhand sideline, a forehand force sends throws into the middle, so some teams switch the mark there to trap the other line. That only works if the whole defence hears the call, so start with the forehand sideline.

Step by step

The offence is in a vertical stack with O1 holding the disc and O2 behind as the dump. The defence forces forehand, so the forehand side, and the forehand sideline, are down the picture.

O3 cuts under toward the forehand sideline and O1 throws it there. D3 follows a step behind.

O3 catches near the line. D3 sets the mark on the inside, between O3 and the middle of the field, so the only open throws run along the line. D2 follows O2 to the dump and stands between O2 and the disc, and D1 picks up O1.

The stack defenders slide toward the line, each staying a step downfield of their cutter.

O5 cuts up the line. D5 is already on that side, so they run with O5 and stay downfield and nearer the sideline.

The stall count is high and there is no open throw. O3 throws up the line ahead of O5, and D5, who was already downfield, gets to it first.

The block is a turnover on the sideline. If O3 had found the dump and the disc had been swung to the middle, the defence would have gone back to its normal force.

To practise it, walk through the play with a full line of seven. Put the disc on the forehand sideline, have the mark call "trap", and check where everyone stands before anyone throws. Then let the offence try the dump and swing at walking pace so the dump defender and the mark learn what they are stopping. Once that is comfortable, run it at game speed from a short pass to the sideline.

The full play

You can take this playbook into your own account and change it for your team, for example drawing the trap on the backhand sideline if your team forces backhand.

Playbooks can also be saved as a PDF if your team would rather have the plays on paper before a game.