Bitcoin skilled a uncommon two-block reorganization on Monday, with competing blocks at heights 941881 and 941882 briefly splitting the community earlier than Foundry USA Pool’s department got here out on prime.
How the reorg unfolded
The occasion started when a number of miners discovered legitimate blocks at almost the identical time, creating a short lived fork.
Foundry mined its personal model of block 941881 whereas AntPool produced a competing block on the identical peak.
ViaBTC then prolonged the AntPool department with block 941882, whereas Foundry concurrently constructed an alternate model of the identical block by itself chain.
Foundry in the end mined seven consecutive blocks on its department, making it the heaviest chain by cumulative proof of labor.
Consequently, the blocks mined by AntPool and ViaBTC grew to become stale — legitimate blocks that fell exterior Bitcoin’s canonical ledger, which means these miners acquired no rewards for them.
Pool dimension and hashrate
Foundry’s dominance in community hashrate probably influenced the end result.
Foundry USA Pool controls roughly 32.2% of Bitcoin’s hashrate, in contrast with 15.7% for AntPool and seven.2% for ViaBTC.
Bitcoin developer “b10c” famous {that a} pool’s likelihood of discovering the subsequent block is proportional to its share of whole hashrate, which means bigger swimming pools have a pure statistical edge throughout short-lived forks.
What occurred to the displaced transactions
Transactions included within the stale blocks weren’t misplaced.
They both already existed within the successful chain or returned to the mempool for attainable inclusion in later blocks.
The episode displays Bitcoin’s consensus guidelines working as designed — nodes reorganized to the heavier chain, restoring a single canonical historical past.
Whereas single-block reorganizations happen often, a two-block occasion is much less frequent however nonetheless a identified consequence of near-simultaneous block discovery and unusual community propagation.