Share Difficulty

Share Difficulty is the difficulty level assigned by a mining pool to intermediate mining results. A computational result that meets this difficulty qualifies as a share and can be used to measure the participant’s contribution.

Share difficulty is normally much lower than blockchain network difficulty. This allows a pool to receive results from miners much more frequently than the network produces complete blocks.

Why Separate Difficulty Is Necessary

Consider a blockchain with very high network difficulty. If every miner were required to submit only results capable of satisfying the network condition, a low-hashrate device might go a very long time without producing a reportable result. The pool would therefore have little practical information about whether the device was working or how much work it was performing.

Share difficulty solves this problem. The pool sets a more accessible threshold and receives regular intermediate results that statistically represent the miner’s work.

Relationship with Hashrate

All else being equal, a more powerful miner finds shares more frequently at the same difficulty. A pool can therefore increase share difficulty for high-hashrate workers and decrease it for lower-hashrate workers.

This automatic adaptation is performed by VarDiff.

Share Difficulty vs. Network Difficulty

Parameter	Share Difficulty	Network Difficulty
Set by	Mining pool	Blockchain network rules
Purpose	Track miner work	Define the block-finding condition
Affects consensus	No	Yes

Changing share difficulty does not mean that the cryptocurrency has become harder or easier to mine. It changes only the frequency of intermediate results submitted by miners to the pool.