Bitcoin’s BIP-110 minority chain has fallen 18 blocks behind the dominant Bitcoin network after a split at block height 961632, highlighting the growing difficulties facing the breakaway version.
At 19:56 EDT on Saturday, BIP-110-aligned mining pool Roughnecks had produced a second block on its chain, at height 961633. The main Bitcoin chain had already advanced to block 961651.
The split followed two years of intense disagreement over BIP-110, which passed its signalling threshold at block 961632. With blocks continuing to build on the dominant chain, the practical consequences of the disagreement are now becoming clearer.
Luke Dashjr, creator of Bitcoin Knots, warned users that they could be exposed to double-spending attacks if they had not updated their software.
“PSA: If you haven’t upgraded to Bitcoin Knots 29.3.knots20260508 (or 29.4) yet, you are now vulnerable to double-spending attacks aided by [Foundry and Antpool],” Dashjr wrote on X.
He added, in bold lettering: “Upgrade ASAP to avoid accepting counterfeit bitcoins.”
Dathon Ohm, the anonymous architect behind BIP-110, also posted on X and continued to insist on his position, although no further wording from that post was provided.
The immediate split began with a contest between Roughnecks and Antpool for block 961632. Antpool won the race on the dominant Bitcoin chain, while Roughnecks’ version of the same block was left on the competing BIP-110 chain.
Roughnecks subsequently mined block 961633, giving the minority chain two blocks in succession.
The fork was made more difficult by a simultaneous adjustment to Bitcoin’s mining difficulty at block 961632. The difficulty rose to 127.48 trillion as the blockchain divided into competing versions.
Bitcoin’s difficulty does not automatically decrease when most miners leave a chain. As a result, Roughnecks and its supporters remain subject to the same 127.48 trillion target while operating with only a small fraction of the computing power available to the main chain.
Unless significantly more hashrate moves to the BIP-110 version, blocks could be produced at increasingly long intervals. That could leave the minority chain waiting a considerable time before it mines enough blocks to trigger its next difficulty adjustment.
A further complication came when Simple Mining, a major hosting company based in Iowa, directed hashrate towards Ocean Mining and mined block 961634 on the dominant Bitcoin chain.
Simple Mining operates with Ocean’s DATUM system, which allows individual miners and hosting companies to create their own block templates. Those templates can include a decision on whether to set the BIP-110 version bit.
The block therefore carried particular significance. Ocean has been closely associated with BIP-110, with Dashjr serving as the pool’s chief technology officer and much of the proposal’s early signalling coming through Ocean and DATUM miners.
However, Simple Mining’s block was mined on the dominant chain. That suggested hashrate linked to Ocean was not acting as a unified group in support of the BIP-110 minority fork.
Roughnecks’ 110th Mining Division celebrated the successful mining of blocks 961632 and 961633, comparing the achievement with “wildcatting” in the oil industry, where prospectors take risks on unproven ground in the hope of finding valuable reserves. Dashjr reposted the message on X, although it remains uncertain whether the effort will ultimately succeed.
Some BIP-110 supporters reacted angrily to the result. “RIP Bitcoin. You just became only another captured speculative asset. Sorry Satoshi, we failed you,” BTCbello, an X user and BIP-110 supporter, wrote.
Matthew Kratter, one of the proposal’s most prominent advocates, said it would now take an “absolute miracle” for the BIP-110 chain to overtake the legacy chain.
Other supporters suggested the minority chain could change its proof-of-work mining algorithm. Responding to Kratter’s latest video, the X account Maitreya Lockwood wrote: “We have nothing to lose by starting new with a POW. So much potential and freedom in being able to see what just clearly happened and make the corrections needed to keep this alive. This is Independence Day for sound and decentralized money,”
Bitcoin developer Chris Guida has also revisited code that could change the mining algorithm on a breakaway BIP-110 chain if the minority network proceeds with such a move.
