Did I forget to mention there is no possible way to determine any specific narrowed down range for an address, that is even if we know the exact start/ end range, what you can only do is to guess a small range and then trying to brute force it, doing that would be equal to searching half the previous puzzle's range, considering even if you could shrink the 66 range to 25%, you'd be searching half of 65's range.

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I have looked at solved puzzles for weeks to find a pattern or to just reduce the search range for unsolved ones, I was able to reduce the range of the next puzzle by 10%, lol.

What you should know, I believe Satoshi placed the keys at least in 50% + of each range, which makes solving them counterproductive financially.