130,827 Latest block · snapshot of Oct 20

Game · medium · 8 min

Difficulty Pilot

Keep Pearl's 194-second heartbeat steady through hashrate shocks

  • How difficulty and hashrate set the time between blocks
  • Why single block times are a lottery
  • WTEMA's time constant, fast versus smooth
  • Per-block retargeting versus Bitcoin's 2,016-block windows

Difficulty Pilot

Keep Pearl’s heartbeat at 194 seconds

Best—

Arcade · difficulty

Hashrate jumps, drops and crashes. Keep the average block time within 10% of 194 seconds.

After each of three shock waves, the average of the last 50 blocks must sit inside the green band.

Level 1 you fly by hand; then you tune Pearl’s WTEMA rule and race it against Bitcoin’s.

  • ↑W harder (difficulty ×1.1)
  • ↓S easier (÷1.1)
  • Shift↑ ↓ big step (×1.5)
  • P pause / resume
  • ←→ pick the time constant (levels 2–3)

Hashrate, shocks and luck are simulated; the rule is Pearl’s. One step is shown with exact integer math on real bits.

Levels

Best —
Runs in your browser · scores stay on this device src/lib/wtema.ts · float simulation, one exact step

How to play

Pearl aims for one block every 194 seconds. Three shock waves hit the network: a GPU farm joins, a big pool leaves, and an outage knocks out most miners for a while. At the end of each wave, the average time of the last 50 blocks has to sit within 10% of 194 seconds (the green band).

Level 1, manual. Blocks arrive four a second. Raise the difficulty when blocks come too fast, lower it when they’re slow. The thin line is the pace: the average block time your current difficulty would give at the current hashrate. The thick line is the 50-block average you’re judged on. The dots are single blocks, and they jump around however well you fly.

Level 2, tune WTEMA. Now Pearl’s own rule flies. Pick its time constant τ and press Run. Every run has the same shocks and the same luck, so only your choice changes the outcome. Find a τ that lands all three waves.

Level 3, race Bitcoin. Your WTEMA against a Bitcoin-style rule that waits 2,016 blocks and then corrects, over 6,048 blocks. Same shocks, same luck: land all three waves and score higher than Bitcoin’s rule.

Keyboard: ↑/↓ (or W/S) change difficulty by ×1.1, with Shift by ×1.5, and P pauses. In levels 2 and 3, ←/→ pick the time constant.

What’s real and what’s simplified

  • Real: the rule. After every block Pearl multiplies the target by 1 + (t − 194) / τ, where t is how long the block took. Mainnet uses τ = 604,800 seconds, one week. Open “One step, exactly as pearld does it” to see the integer version from the site’s wtema.ts applied to the real mainnet bits.
  • Simplified: hashrate, the shocks and the luck are made up, and the runs use floating point for speed. The game compresses days into minutes. That’s why short time constants win here, while mainnet’s one-week constant would still be catching up. It’s smooth but slow: after Pearl’s launch, blocks took weeks to settle at 194 s.
  • The pace line is something no real node can see. Nodes only see block times, and that’s exactly the information WTEMA uses.
  • The Bitcoin-style rule here runs at Pearl’s 194-second spacing and allows at most a ×4 change per window, like Bitcoin’s.

Suggested