I was stubborn enough to continue playing the 69 lottery.

So... 17741 trillion keys later (17741059321436160 keys): no 53 bits or better H160 prefix found, even though the probabilities says I have 86.04% chances to have at least one 53+ find.

The only 53 bits or better match I managed to find was the freebie key with the exposed public key posted here yesterday. This happened once I queued the range where that key was found, and validated that everything was actually working as expected.

Let's call it bad luck. For reference, I switched regularly every few hours between 3 main approaches:

- random unique range (I'm scanning 38-bit ranges, so 1.07 billion total ranges)
- "skip N ranges" according to the best prefix length found in previous scans
- "pad range": create a ban area around a range according to best prefix, skip it if attempting to choose it as next scan range.

Also some filtering wizardry of the entropy of the range bits ("does it look suspicious?").

My best hashrate was around 560 GK/s. My system uses the cheapest possible interruptible GPU rentals, and allows resuming interrupted scans, from the exact last known checkpoint sent to the server, via a real-time web socket.

Well, there goes my 1 in 16643 chances to find the 69 key.
Total scanned portion of the full range was 0.006009%.

16291 total 40+ bits keys found as PoW.

I'm gonna spend the rest of the budget allocated for this experiment to play the national lottery.