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For the little bit I understood so far about the mining process, it seems to me that "finding" a block is very very very difficult for a CPU/GPU.
However, since it is done by brute force, it seems to me that there is a very small chance (has anyone calculated how much?) of a single cpu miner to find a block very fast in a few first tries, hence hitting the jackpot of 25 BTC.
Is this theory correct?