What is a share?
Share is a data packet containing a potential solution to a block. A share is not suitable for adding to the blockchain as a separate block but is one of the complex "solutions."
A mining pool needs shares to assess each miner's contribution to the overall pool effort in finding a block and fairly distributing rewards, building a miner's hashrate chart, and determining whether the miner is actively contributing to the network.
What is the share difficulty?
The Share difficulty in mining determines how difficult it is to find the correct hash to create a new block in the blockchain. The higher the difficulty, the more computational power and time are required to find a suitable hash. Workers search for hashes that meet the conditions of share difficulty and when such a hash is found, it is sent for verification to the mining pool.
What is the purpose of the share difficulty?
The difficulty of a share is adjusted to ensure that miners work comfortably, to see detailed statistics of their work, and prevent the pool from being overwhelmed by the number of received shares.
Workers produce billions of hashes per second, but no one pool can accept that many shares and verify them. Therefore, based on your hashrate, the pool sets a difficulty value at which it will accept shares from you. The higher the hashrate, the higher the difficulty of the shares. During calculations, a worker may find a hash that matches the difficulty of share and then send it to the pool.
Example:
You mine with a device with a hashrate of 100TH/s, and the mining pool sets your share difficulty to 5,000,000.
You will only be rewarded for shares with a difficulty higher than 5,000,000.
If you increase the hashrate to 200TH/s, the pool will adjust your share difficulty so that you do not send shares too quickly.
Network difficulty vs share difficulty
The network difficulty is a mechanism built into the self-regulation of a coin. The more miners (network hashrate), the higher the difficulty, and network participants make less - and vice versa. Roughly speaking, difficulty is a defensive reaction of the network. Difficulty for each coin is calculated in a different way.
Example:
BTC - the difficulty is adjusted every 2016 blocks (every 14 days) so that the average time between blocks is 10 minutes.
LTC - recalculation of the mining difficulty in the Litecoin network is performed on each block.
Why does the pool set high shares difficulty?
The main factor is the optimization of the work of miners on the pool. Shares with low difficulty are not always good. If the user is mining at too low a difficulty, the mining hardware can spend a lot of time sending and receiving data from the pool server, i.e., it will be idle, which will cause rejects.
The share difficulty does not affect the income as the payouts are
proportional to the hashrate of the miner. With more difficult shares the device will find the correct block solution without equipment downtime.