BIP110 Fork Simulator

Configure Simulation Parameters

BIP110 gives up after wasted blocks BIP110 blocks stranded off the most-work chain. Standard gives up after wasted blocks Standard blocks reorged out by BIP110. Either side gives up when blocks behind Gap from the valid chain with most work. Random seed Re-try increments this seed before running.

These are model assumptions, not consensus rules. The seed makes the random draw reproducible; 144 is roughly one day of blocks.

Thresholds near a 2,016-block retarget period make the constant-difficulty simplification weak.

What BIP110 actually proposes

Reduced Data Temporary Softfork is a consensus change proposal that aims to temporarily restrict several data-carrying constructions for 52,416 blocks, roughly one year after activation.

Rules, in short: limits or invalidates specific scriptPubKey, OP_RETURN, PUSHDATA or witness-item, undefined witness/Tapleaf version, annex, control-block, OP_SUCCESS, and OP_IF/OP_NOTIF constructions.

Split points in the draft: mandatory signaling starts at 961,632; reduced-data rules activate one difficulty period after lock-in, no later than 965,664.

Sources: BIP110 draft, BIP9, BIP8, and Bitcoin Core chain.h. Last reviewed against the BIP110 draft: 2026-06-20.

Model assumptions

Simplifications

Constant difficulty and equal work per block.
Aggregate hashrate draw, not a full network simulation.
Standard means miners not enforcing BIP110's new rules; they follow the valid chain with most accumulated work.
For the fork race, Standard-mined post-split blocks are modeled as non-signaling or non-compliant with BIP110; real non-enforcing miners can still produce compliant blocks.
The model starts from last common block n; the same simplified fork-race mechanics apply after either Activation split point.
Ties are simplified as first-seen: miners stay on their current tip.
Quit thresholds are human/economic assumptions, not Bitcoin consensus rules.
The model holds difficulty constant on both chains and treats equal-difficulty blocks as equal work.

Observed signaling

Version-bit signaling is scanned from current-period blocks via mempool.space and cached by the local server. The observed signaling preset maps the current aggregate bit-4 signal rate into a demo hashrate percentage; it does not mean those miners will enforce BIP110 later.

Last reviewed against the BIP110 draft: 2026-06-20.

Credit & license

This simulator's fork visualization was built starting from 0xB10C's fork-observer and adapts portions of its code. fork-observer is released under the MIT License; its copyright and permission notice are reproduced below, as that license requires.

MIT License

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Select BIP110 Hashrate to Simulate

Simplifications

Observed signaling