Of all the factors that affect your 67 Challenge score, hand position is the most overlooked — and often the most impactful. Players obsess over how fast they can move, but if the AI isn’t detecting your reps, speed is irrelevant.
Here’s a complete guide to hand position for maximum detection accuracy.
Why hand position matters so much
The 67 Challenge uses Google’s MediaPipe Hands model to detect 21 landmarks on each hand. For a wave to be counted, the model needs to:
- Detect both hands simultaneously
- Observe one hand (or both) moving in and then back out of the frame plane
- Distinguish intentional wave motion from random movement
Get the position wrong and the model either misses hands entirely or counts your motions erratically. Get it right and every rep lands.
The correct starting position
Before the timer starts, position your hands like this:
- Palms facing the camera — the back of your hands should face away from you
- Fingers spread slightly — not clenched, not rigid, just naturally open
- Hands at shoulder width — roughly in line with your shoulders, not crossed or touching
- Hands at chest to chin height — centered in the camera view
This gives the AI the clearest possible view of both hands and the most landmarks to work with.
The wave motion
A correct wave rep is a controlled in-out movement:
- Start with hands at mid-position in frame
- Move both hands toward the camera (closer to the phone) — or raise them upward
- Move them back to starting position
One complete cycle = one rep. The key is that the motion must be consistent. Random arm flailing often registers as fewer reps than smooth, rhythmic waving — even if it looks faster.
Common mistakes
Crossing your hands: Moving one hand across to the other side breaks detection because the model gets confused about which hand is which.
Moving in the horizontal plane only: Side-to-side wrist wiggles are often not detected as wave reps. The in-out depth motion (toward and away from camera) or an up-down motion works much more reliably.
Uneven hand height: If one hand is significantly higher than the other, the model sometimes loses track of the lower hand against the background.
Moving too large: Wide arm movements send your hands to the edge of the frame where detection accuracy drops. Keep movements small and centered.
Lighting and background tips
Your hand position works best when the background is plain and relatively dark. A white wall works well. A cluttered, busy background makes it harder for the model to isolate hand landmarks.
Make sure your hands are well lit from the front, not from behind. Backlighting creates silhouettes, not hand landmarks.
Single-hand mode?
Currently, the 67 Challenge requires both hands. A single well-detected hand with perfect technique will still score zero if the second hand isn’t visible. If you find one hand keeps dropping out, focus on keeping it more centered in frame rather than trying to move faster.
The ideal technique looks calm and deliberate from the outside — not frantic. Players who score in the 60s and 70s almost always have smooth, rhythmic, controlled motion rather than the panicked arm-waving you might expect. Master the hand position first, then work on increasing speed within that controlled range.