Mining a valid BTC block solo is so rare that the event has occurred only 270 times out of the 700,000 blocks produced in the last 13 years.
Solo Bitcoin miner defies odds to mine valid BTC block, gets $150K block reward [cointelegraph]
Mining a valid BTC block solo is so rare that the event has occurred only 270 times out of the 700,000 blocks produced in the last 13 years.