← experiments

28 October 2026 · Day 28 · Built with Claude

The tail wags the dog

In a sheepdog trial it looks as if the shepherd steers. Whistle to the dogs and find out how much you do. They read the sheep and know the job without you, and a hands-off run of the same flock keeps score.

The shepherd stands at the bottom. The fold's gap faces up the hill. Each dog wags harder when it is working on its own, and less when it is doing as it's told.
Sound off

Whistle to

In the fold
0 / 24
Hands-off
0 / 24
Clock
0:00

The sheep steered the dogs 100%You 0%

No whistles yet.

Start the trial and leave it alone first. The dogs know what to do.

Try this

  1. Start a trial and don't whistle at all. The dogs run out wide, fetch the strays, bring the flock round to the gap and pen it.
  2. Start a new trial and whistle as much as you like. Compare your count with the hands-off flock's.
  3. Turn "How well they listen" down. Your whistles matter less, and the dogs often do better.
  4. Try one dog, then six.

Who is steering whom

Nobody gives the sheep orders. Each one keeps clear of the others, closes up on its nearest neighbours and moves away from a dog that comes too close. That's all. The dogs read the sheep. If one has strayed, a dog goes round behind it and brings it back. If the flock is together, the dogs get behind it, on the far side from the fold, and walk it in. They run wide so they don't split it.

So most of the steering goes from the sheep, through the dogs, and only then to the shepherd. Many of the shepherd's whistles tell a dog to do what it was about to do anyway. The score counts both: how much of the dogs' running your whistles set, and how many of them told a dog what it was already doing.

In this model a second dog barely helps, a third helps a little, and more than that makes little difference. Hands-off, one dog pens 24 sheep in about two minutes of trial time, and three or more dogs take about a minute and three-quarters.

The words

Outrun
The dog's wide run from the shepherd's feet to behind the sheep.
Come bye
Go clockwise round the sheep.
Away to me
Go anticlockwise.
Walk up
Walk straight in towards the sheep, steadily.
Lie down
Stop, and drop.
That'll do
Finished. Come back.
Brace
Two dogs worked together. Each learns its own whistles, so the shepherd can send one without moving the other. Here every dog has its own pitch.

Where the rules come from

The sheep and the one-dog rules are Daniel Strömbom and colleagues' 2014 model of shepherding, which needs only two dog behaviours, collecting and driving, to pen a flock. Here it is stretched to several dogs that share out the strays and spread along the back of the flock, with the fold as a round stone sheepfold. The whistles are made up, as every shepherd's are.