Best Difficulty as a Benchmark.. Best Difficulty tracks the most significant share a miner has found. While it may not be enough to solve a full block, it shows progress and capability.

Winning a Block... If a miner finds a hash below the Bitcoin network's current target difficulty, they successfully mine a block and receive the full block reward.

Best Difficulty is an indicator of mining efficiency and luck, showcasing how close a miner has come to solving a block.