The myth of the sideline trap in ultimate Why “trap for one” is a bad idea that usually gets your team broken and scored on

“Trap for one!”

It’s one of the most common tactics in ultimate — to temporarily switch the force and “trap” a thrower against the imaginary wall of the sideline, supposedly reducing his passing options to a thin wedge of upfield targets along the sideline or a straight-back dump. But the trap is a trap! Even when cleanly executed once, which is unusual, it's often still unclear when to switch back to the original force, or just impossible for six running defenders to move that fast even if they know exactly what the mark is doing. The uncertainty is defense doom. Ironically, a change of force is far more dangerous to the defense than it is to the offense, and usually leads to a dangerous break of a confused force within the next three passes.

The evidence

In the summer of 2012, I took notes on about fifty sideline traps in mid- to upper-level Vancouver Ultimate League play. This was certainly not ideal or precise methodology. Nevertheless, the results seem pretty informative.

Clearly the sideline trap is not working the way players hope it will. Speaking as a handler, I actually want my check to try to “trap” me: it’s a gift!

A sideline trap can work on a weak thrower, but most of the time it just causes defensive confusion, and definitely does not work the way players hope it will.

Disclaimer: of course it can work sometimes

A sideline trap can work, but the point is that it usually does not.

The sideline trap works best on weak throwers who crack under minimal pressure, and it can work with a team of sharp defenders who can respond like a well-oiled machine to force switches. But how many trap situations does this really describe in the upper divisions of a typical city league? Almost none!

No half-decent player is so easily intimidated, and "well-oiled” applies only to the best teams, coached and drilled, with the discipline for rapid, consistent reactions to a call — which is what the sideline trap requires.

The hope and promise of the sideline trap

You’re on D! The disc is dead out of bounds on the break side. Everyone’s got a moment to catch their breath while your check trots out to fetch the disk.

You’ve been forcing away — that is, you’ve been interfering with throws to the home side. You’ve been doing a good job, effectively stopping any (reliable) throws to half the field, so your mates don’t have to worry about covering both sides of their checks at once. That’s what a good force is all about.

As your check comes strolling back to the sideline, you get a bright idea: I can trap him! you think. Here's your reasoning …

It’s madness to force him away like you have been, right? The away-side is the entire field! Why “force” him to throw to the whole field? Why not just get between him and the field, so that any throw he tries to make infield is going to have to go through you?

Sheer genius!

Besides, you’ve seen other players do it tons of times. There must be something to this trapping stuff.

“Trap for one!” you bellow.

Translation: “Don’t worry! I’ll save you all! I will singlehandedly prevent the disk from being thrown anywhere worth throwing it to. The O will be thwarted! They’ll have nothing! Bwa ha ha ha!"

That’s what you hope. That’s your promise.

What usually actually happens when you trap for one

You’re on O! Some dude is “trapping” you against the sideline. Excellent: the D will be in shreds. He yells “trap for 1!” in your ear and — like a well-oiled machine? — three defenders uncertainly move over the other sides of their checks, while the other don’t move because:

  1. They simply did not hear the call. It was yelled away from them. Their brains are low on oxygen.
  2. They heard it, but they aren’t sure what to do about it. Many players are momentarily disoriented by a force switch. Most do understand the concept, but need a moment to think about it — it’s just not automatic and quick.
  3. They get it, they know what to do in theory, but they’re too tired to move fast enough to actually completely reverse their field position. In many cases, their check is already moving to exploit the opportunity and actually just can't be stopped by a defender who finds herself on the wrong side.
  4. The most alert players can clearly see that their check still has an excellent receiving option on the new force side, because the thrower can easily break the new force upfield with an OI backhand — an easy, high percentage throw that even weaker handlers can usually pull off.

The count begins and you now have three receivers open on side, and three receivers open on the other, and all of them with checks who are a bit disoriented — it’s like a handler’s dream. Because the sideline is not actually a “wall” that you can be “trapped” against, you pivot away from your check, putting your throwing hand a good 3 feet out of bounds, and lob an easy 10-yard backhand diagonally back into the field. It is received several yards inbounds. This is a fine upfield movement, but it's not the best part. The best part is how much a shambles the defense is in.

No more than a few seconds have passed. Three defenders are still on the wrong sides of their checks, of course — when and why would they have switched? — giving your team more options than a supermodel with a PhD. The next mark puts back on the usual force, but the rest of the D doesn’t even remotely have time to react and get back onto the right sides of their checks. Which means the next pass is effortless … and the one after that, as likely as not, is a score.

And that’s just a typical post-trap meltdown. It not even the worst case scenario.

Or worse!

The above post-trap meltodwn assumed that half the defenders actually responded to the trap call by switching sides. Many times I have seen far worse: the trap is set up rapidly, the call made weakly, and the defense mostly or entirely fails to switch the force, leaving the O open for a series of easy passes close to the line.

This disaster is common. Many players think that the trap is not just an occasional clever trick, but actually standard: that you’re supposed to do it when you get close to the break-side sideline. Because they think it’s standard, they don’t really emphasize it; they think that the rest of the team already understands, or should, without necessarily even being told. So they call it quietly, or late, or not at all. Doing it that way barely even qualifies as a “sideline trap” — it’s really just a sloppy failure to hold the force.

The impulse to “trap” probably accounts for a lot of otherwise inexplicable failures to force and howling of “no break! no break!” from puzzled players on the sideline.

But there’s a lot of trouble with traps even when they are used more decisively.

The trouble with traps

There are many basic reasons why the trap is generally a weak strategy:

  1. Consistency of force is by far a more important factor than the effectiveness of any one force.
  2. The sideline isn’t actually “trapped” against anything. The disc is free to be thrown on a lovely out of bounds arc.
  3. Player don’t hear the call and lack confidence in their response to it.
  4. It’s damned near impossible for checks to respond to a rapid change in the force.
  5. The next reception routinely confuses everyone if it’s anywhere close to the sideline still.

That’s a lot of problems!

The force is too important to screw around with

The force is critical to defense in ultimate. It’s simple math: the force determines position for six other players, and thus it is six times more important than the positioning of any single other defensive player. As the mark, your positioning makes it either possible or impossible for six other players to do their jobs.

Defenders simply cannot interfere with a throw that is on the other side of their check. Six defensive players have been taken out of the play. And so — let me really “hammer” this home — a break-force throw has six open receivers. A throw to the break-side is not only a nearly guaranteed reception, but a nearly gauranteed reception after that. Forces, like boots or hearts, o when they start, they really start to fall apart.

And so breaking the force is by far the easiest path to a point in ultimate.

A break is especially brutal because defenders do not generally dare to try actually move to the break side of their checks — because, of course, they would then be leaving their checks open on the force side. And the next mark is presumably going to (more or less) hold the force. So defenders can’t even really respond to a break by switching sides. Really the only hope of stopping a break from doing a lot of damage is to get a good strong forcing mark back on the next thrower.

And so consistency of force is by far more important than trying to interfere with a single pass on the sideline. Even if you succeed, if your team does not immediately get back to the “proper” force after that, you are all screwed.

The sideline is not actually a wall, people

Imagine how effective it would be to trap if the sideline really was a wall: if the thrower could not pivot out of bounds, if a throw up the line really had to be completely in bounds along its whole flight path. The ultimate field would feel like a canyon. Yikes. If there was actually a wall there, I sure wouldn’t want to be trapped against it!

But there’s not a wall there. And no half-decent thrower acts like it or feels that pressure.

The perception of the sideline-as-wall actually ironically tends to afflict the defense, not the offense. The defense generally irrationally avoids positioning themselves out of bounds, making it a terrific place for the thrower to pivot into and throw the disc through. Whenever I’m “trapped,” I really feel liberated: like I’m being given a space to work with!

I can even huck! I can easily do a hard, clean backhand OI, because the trapping defender is very unlikely to move out of bounds to try to interfere with it. Better yet, half my receivers are probably going to be open for it.

Anything but a trap! Please! Anything!

Traps make the next force ambiguous

Most people in the Vancouver Ultimate League call “trap for one” — emphasis on the one — in a doomed attempt to clarify the defensive strategy. It’s ironic, because a trap is a sure-fire way to muddy the waters: ambiguity is exactly why trapping tends to backfire.

What will the next force be? Trap for “one” implies that the next force should be back to the normal force, and the running defenders should be ready to reverse their positioning at high speed.

But what if the next reception is still on the line? Or 3 meters in bounds? Which is common?

More irony: the next force is only obvious if your trap is broken! If the disk has been received mid-field, it’s clear that the trapping is now over … but you’ve already been broken. Bummer.

If you “succeed” in forcing a throw up the line though, you’ve actually created confusion: should the next mark continue to trap? Or revert to the original force? If the disk is received on the line, the next mark is quite likely to choose to trap as well, effectively over-ruling you: it is no longer a trap for “one.”

But most confusing of all is the (quite likely) reception just 3–5 three meters in bounds. What does the next mark do with that?

Some will hold the trap force because it’s still almost on the line. Others will switch it back to the original force, because, duh … well, there’s a list of good reasons, but the most obvious is that it was “trap for one,” not “trap for two”!

In short, trapping creates an untenable situation where the entire team is waiting to hear what the force is this time. Hundreds of times, I have seen a trap force followed by this kind of field chatter:

“What’s the force?”

“Hold the force!” Which one, though?

“Force away!” Better. But will the mark hear? Agree?

“Switch the force back!”

“Trap again!” But it’s not even on the line any more.

“No break, no break!”

And, of course:

“Broken!” But by this time it’s often not even clear which force was broken! The trap force? The regular force? For the defensive player busy watching and chasing his check, it is often impossible to know. The call “broken” is supposed to be like an “up” call that gives you a clue where to defend, but if you don’t know which way “broken” is the call is really just useless, and it might as well have been “bad news!”

Mass confusion and meltdown of the force is the normal response to a trap when the circumstances are anything less than ideal. And all this ambiguity is far more dangerous the D than the trap is to the O. Running defenders simply cannot do their jobs if they don’t know what the force is. Make it unclear for even 5 seconds, and the most likely outcome is break, break, score.