BIP-110's Fork Mines Two Blocks in Eight Hours and Stalls

Bitcoin's data-limits fork lasted a weekend, and barely that. BIP-110, the proposal from Luke Dashjr's Bitcoin Knots camp to cap what data the chain will carry, entered its mandatory signaling phase at block 961,632 having drawn 51 of the prior 2,016 blocks, or 2.53%, in voluntary signaling. Nodes enforcing the rule began rejecting blocks that did not signal, and a minority chain split off at block 961,633. It mined two blocks in its first eight hours. Mainnet advanced 48 in the same stretch. By Sunday the fork sat 98 blocks behind, with no third block found and the gap still widening.

What the fork was asking for

BIP-110 would cap most new output scripts at 34 bytes, limit OP_RETURN outputs, the standard slot for arbitrary data, to 83 bytes, and hold certain data pushes and witness elements to 256 bytes; in plain terms, a rollback of the chain's data-carrying uses. Activation needed 55% of a 2,016-block window, or 1,109 signaling blocks, ahead of a lock-in deadline at block 963,648. It got 51. Mandatory signaling, the phase that opened this weekend, is the enforcement step: nodes running the new rules treat any block that fails to signal as invalid, which pushes them onto their own chain if miners do not come along. Miners did not come along. Nothing changed for everyone else. A block that does not signal stays fully valid under the rules the rest of the network runs, so mainnet carried on as if the deadline did not exist.

The 350-day trap

The fork chain inherited mainnet's full difficulty, which had just risen 0.99% to 127.48T at Saturday's retarget, while attracting less than 3% of hashpower. Difficulty resets only every 2,016 blocks, and the clock runs on blocks found, not on time passed. At the fork's pace, its next adjustment is an estimated 350 days away, and every hour without a block pushes that date further out. A chain in that position is effectively unminable: too slow to reach its own retarget, too weak to attract the hashpower that would speed it up.

Snapshots of the deficit vary by the hour they were taken. KuCoin's flash logged the fork 26 blocks behind at an earlier reading; the 98-block gap is the state on Sunday. The two figures describe the same collapse at different points, and they move in only one direction.

Five months of signaling, 2.53% of blocks

The campaign was not short. The first block signaling for BIP-110 was mined by Barefoot Mining through Ocean Pool on 1 March. Five months of voluntary signaling later, support stood at 2.53%, and the argument had run loudly on both sides all summer; Michael Saylor published a 110-point case against the proposal in July. Sources even disagree on when the mandatory phase began: crypto.news puts it at 8 August, BIT Insights at 7 August. Both name block 961,632, and the block height is the honest anchor.

A deadline that will pass quietly

The lock-in deadline was never in reach at 2.53%, and on mainnet the window will simply close with nothing changed. What remains is the record. A soft-fork campaign ran five months of signaling and converted one block in forty; its chain-split fallback produced two blocks and stopped. Nodes still enforcing BIP-110 now sit on a chain that cannot realistically add a third. The argument over bitcoin's data limits is not settled. This round of it is.