Mining pool

In the context of mining, a mining pool is the pooling of resources by miners, who share their processing power over a network, to split the reward equally, according to the amount of work they contributed to solving a block. A "share" is awarded to members of the mining pool who present a valid proof of work that their miner solved. Mining in pools began when the difficulty for mining increased to the point where it could take years for slower miners to generate a block. The solution to this problem was for miners to pool their resources so they could generate blocks more quickly and therefore receive a portion of the block reward on a consistent basis, rather than randomly once every few years.

Mining pools may contain hundreds or thousands of miners using specialized protocols. In all these schemes ${\displaystyle B}$ stands for a block reward minus pool fee and ${\displaystyle p}$ is a probability of finding a block in a share attempt (${\displaystyle p=1/D}$, where ${\displaystyle D}$ is current block difficulty). A pool can support "variable share difficulty" feature, which means that a miner can select the share target (the lower bound of share difficulty) on his own and change ${\displaystyle p}$ accordingly.

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