Definition
Stubborn mining is a family of strategies that generalizes selfish mining by changing how an attacker behaves when it falls behind in a private chain race. Classic selfish mining concedes and publishes when the honest network catches up; a stubborn miner instead keeps mining on its hidden branch, betting that persistence can convert an apparent defeat into a victory under the right conditions.
Degrees of Stubbornness
The 2015 research that introduced stubborn mining defined several variants by how aggressively the attacker clings to its branch: lead stubborn mining, equal-fork stubborn mining, and trail stubborn mining. Each tunes the decision of when to reveal withheld blocks versus continue building privately. By selecting the right degree of stubbornness for a given network position, the attacker can extract more relative revenue than the original selfish strategy, with reported gains up to several percent beyond selfish mining in favorable conditions.
Why It Matters
Stubborn mining demonstrates that the threshold for profitable deviation from honest mining is not a single fixed point but a strategy space. The same withheld-block mechanics that drive a chain reorganization can be optimized, and combining stubbornness with pool-infiltration tactics produces even stronger hybrids. The practical defense is the same structural one that bounds all such attacks: keeping hashrate well distributed so no actor can sustain a private branch long enough to profit.
For context, compare stubborn mining with the block withholding attack and the longest-chain rule that all these strategies ultimately exploit.
See hashrate distribution in the pool centralization tracker.
In Simple Terms
Stubborn mining is a family of strategies that generalizes selfish mining by changing how an attacker behaves when it falls behind in a private chain…