The numbers behind 10 years of Bitcoin Puzzle hunting.
50 of 82 puzzles were solved in 2015 alone — the easy ones. After that, each year brings fewer solves as difficulty doubles per bit.
Where in the search range was each key found? Average: 51.4%. The distribution is roughly uniform — there's no "lucky zone."
Each puzzle doubles the search space. Puzzle 71 (lowest unsolved) has ~1.2×10²¹ keys. Puzzle 160 has ~7.2×10⁴⁷ — more than atoms in the solar system.
The gap between puzzle 70 (solved 2019) and puzzle 71 (unsolved) represents a 2× increase in difficulty. Puzzle 71 has 1.2×10²¹ keys — at 5 billion keys/sec, that's ~7,600 years for a single GPU.
The gap between puzzle 130 (solved) and 131 (unsolved) is even more stark. Without a known public key, brute force is physically impossible.
Puzzles with known public keys (135, 140, 145, 150, 155, 160) can use kangaroo algorithms needing ~2^(N/2) operations instead of 2^N.
For puzzle 135: that's ~2⁶⁷ vs 2¹³⁵ — a reduction of 2⁶⁸, making it potentially solvable with coordinated GPU power.
2015: Puzzle N had 0.001 × N BTC. Puzzle 66: 0.066 BTC. Puzzle 160: 0.16 BTC.
2017: Funds from #161–256 moved to #53–160, increasing rewards ~10×.
2023: 872 BTC added. Puzzle 66: 6.6 BTC. Puzzle 160: 16 BTC. Total pool: ~1000 BTC.
Claimed: ~72 BTC across 82 solved puzzles.
Remaining: ~916 BTC across 78 unsolved puzzles.
Avg per solved: ~0.88 BTC (skewed by low-numbered puzzles).
Avg per unsolved: ~11.7 BTC.