BIP-110 Fork Frozen After Two Blocks
Bitcoin’s BIP-110 split widened further on Aug. 9, with the enforcing branch still unable to produce a third block hours after mandatory signaling began Saturday. The latest snapshot showed the minority chain stuck at block 961,633 while Bitcoin’s dominant, non-enforcing chain had reached 961,744. That increased the gap to 111 blocks from 88 earlier Sunday.
BIP-110 enforcing nodes began rejecting non-signaling blocks at height 961,632 on Aug. 8. Roughnecks then produced an alternative block at that height and followed it with block 961,633. OCEAN’s BIP-110 block record showed that Roughnecks mined the first block using its DATUM system at a difficulty of 127.48 trillion. Progress stopped shortly afterward.
OCEAN’s BIP-110 mining endpoint showed its latest block remained 961,633 roughly 17 hours later, with displayed hash power around 257 PH/s at the latest retrieval. Meanwhile, the non-enforcing Bitcoin chain continued adding blocks at its normal pace. The gap had reached 98 blocks when Bitcoin stood at 961,731 earlier Sunday; newer monitor data showed another 13 Bitcoin blocks were added without a corresponding BIP-110 block, bringing the difference to 111.
The stall offers the clearest test yet of how much mining support BIP-110 has attracted. Only 51 of the 2,016 blocks in the previous difficulty period signaled for the proposal, equal to 2.53%. Since the mandatory window started at block 961,632, the monitor had recorded zero signaling blocks among the first 113 blocks on the dominant chain.
Bitcoin worked exactly as designed. BIP-110 was free to fork, and the network was free not to follow. The result was decisive: about 99.85% of Bitcoin’s hashpower stayed with Bitcoin. The BIP-110 branch mined only two blocks and is already more than 80 blocks behind. — Michael Saylor
Why the Minority Fork Is Struggling to Add Blocks
The branch has not technically ceased to exist. Miners can still direct additional computing power toward it and attempt to extend its chain. However, the latest data provides no evidence that enough hash power has arrived to restore anything close to Bitcoin’s regular block production rate.
The Difficulty Adjustment Problem
The problem comes from Bitcoin’s difficulty adjustment system. BIP-110 split away at the start of difficulty period 477, but the enforcing branch inherited the same mining target as the dominant chain. Losing most of its mining power therefore did not immediately make its blocks easier to find. OCEAN records the difficulty at 127.48 trillion.
Bitcoin normally recalculates difficulty after a 2,016-block period. Since the BIP-110 branch has produced only blocks 961,632 and 961,633 in the current window, it still needs to work through the remainder of that period before a normal retarget can provide relief. With block production already measured in many hours rather than roughly ten-minute intervals, the time required could become extremely long unless additional miners join.
Saylor’s Hashpower Rejection Estimate
Michael Saylor, executive chairman of Strategy, seized on that weakness Sunday. In a post, he said “about 99.85% of Bitcoin’s hashpower stayed with Bitcoin” and called the result decisive. That 99.85% figure is Saylor’s estimate rather than a measurement published by the Bitcoin protocol or BIP-110 specification.
Saylor separately estimated that, at “~0.15% of Bitcoin’s hashpower,” the fork could take “~25 years” to reach its first difficulty adjustment. That projection should also be treated as an estimate based on the hash power assumption he used at the time. Mining power can enter or leave either branch, so the expected timeline can change sharply.
Mandatory Signaling Continues Despite Miner Rejection
The unusual feature of BIP-110 is that missing its voluntary signaling target did not end the deployment. The official specification sets a 55% threshold during voluntary signaling but also includes a mandatory window between blocks 961,632 and 963,647. Nodes enforcing the proposal reject blocks during that period unless their version field signals bit 4.
The previous difficulty period ended with just 51 supporting blocks out of 2,016, or 2.53%. Period 477 has been even more one-sided on the dominant chain so far. At block 961,744, the monitor counted zero signaling blocks out of 113 produced since the new period began.
This is why BIP-110 can create a minority branch despite low miner support. Nodes running its rules reject blocks that ordinary Bitcoin nodes accept, causing the two groups to disagree about which blocks are valid. The dominant chain retains far greater observed mining activity, while BIP-110 enforcing nodes remain on the two-block branch.
Adam Back had warned before the split that enforcing BIP-110 without broad support could divide the network. Supporters, including Bitcoin Knots maintainer Luke Dashjr, have instead argued that temporary consensus restrictions are necessary to curb non-monetary data storage. These remain opposing positions in the broader dispute over Bitcoin block space.
Replay Risk on the Two-Block Chain
The stalled branch also leaves a practical issue for anyone considering moving pre-fork coins. BIP-110 does not inherently give those balances replay protection, meaning a transaction signed on one branch can potentially remain valid on the other under some circumstances.
Users were warned that attempting to sell coins on the minority fork without first separating balances could expose corresponding BTC on the dominant chain. The danger arises because both histories began with the same pre-split transaction outputs.
The risk does not mean someone automatically gains control of an entire Bitcoin wallet. Rather, a transaction valid on both chains could be copied and rebroadcast, potentially moving the same transaction inputs on each network. Users who leave pre-split coins untouched do not create a signed transaction that can be replayed.
The economic relevance of that issue will depend partly on whether exchanges, wallets and users begin assigning value to the minority chain. So far, its two-block history and slow production leave little infrastructure for normal transfers or trading.
What Happens Next for BIP-110
The next formal checkpoints remain block based. Under BIP-110, mandatory signaling continues through block 963,647. The proposal is designed to enter LOCKED_IN no later than block 963,648, then move to ACTIVE one difficulty period later. Its actual reduced-data consensus rules would begin at block 965,664 and run for 52,416 blocks, or roughly one year at Bitcoin’s intended block rate.
Those heights are straightforward for the dominant Bitcoin chain to reach if current block production continues. They are much harder for the enforcing branch while it remains at 961,633. The two chains can therefore reach nominally identical block heights on very different calendars.
BIP-110 supporters have also prepared a more radical fallback. An Aug. 1 branch maintained by Chris Guida contains 12 commits involving a potential proof-of-work change, including code for selecting another algorithm and configuring a hard fork time. No activation time is set in the code.
Guida has described the work as contingency code rather than an immediately scheduled fork. That means the present BIP-110 split remains governed by Bitcoin’s existing proof-of-work difficulty unless supporters adopt another change later.
For now, the latest measurable trend remains one-sided. At 15:27 UTC Sunday, Bitcoin had extended the gap to 111 blocks, BIP-110 had not produced a third block, and no block in the dominant chain’s new difficulty period had signaled support. Whether that changes depends primarily on miners directing substantial new hash power toward the enforcing branch.
