Vanishing Holds: The Shrinking Problem

Each group starts with a traverse where every rung is open, and after each round a rival group "removes" a hold by clipping a clothespin to it. Students have to reread the route and find new solutions as conditions change.

How to play

1. Groups of 4 per wall-bar section: each group climbs its open traverse once (4 min).
2. Round 1: the group next door clips two pins on rungs that are now off-limits; the whole group tries to get across (5 min).
3. Rounds 2 and 3: two more pins each time; the group gets one minute to plan before climbing (8 min).
4. Final round: how many pins can the traverse take? Count the max at which at least two members still finish (5 min).
5. Debrief: which removed hold hurt most and what technique solved it (3 min).

Rules

• Pins go on only when nobody is on the traverse.
• The finishing step-down rungs can't be removed.
• Feet under 1 m off the floor.
• Touching a pinned rung means starting over.

Variations

Adaptations

• Students with visual impairments: swap pins for rough tape they can feel, and the group describes the route aloud.
• Hand injury: design the removals for the rival group and referee.
• Nervous students: their traverse keeps one "safe" rung that is never removed.

Learning goals

• Reread a route when the holds change.
• Plan as a group before acting.
• Set fair challenges for the rival group.

Equipment for a class of 25

• wall bars: 10
• gym mats: 8
• clothespins: 40

Teacher tip

Clothespins are easy to see from far away; tape in an X works if you have none. The classic mistake is taking out the key rung in round 1: ask them to remove the easy ones first.

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