# Experiments

> The lab's named search experiments, one section per researcher. Each is a real run against Eternity II with its idea, its best board, and the questions it left open. Raphaël Anjou's notebook is here in full; the notebook is open to anyone else's.

- Canonical page (with interactive figures/demos): https://eternity2.dev/research/lab/experiments/
- Updated: 2026-07-21

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Experiments are named search runs against Eternity II, each written up with
its idea, its best result, and the questions it left open. They are credited
page by page to the researcher who ran them, and gathered into a section per
researcher. This is one corner of the community's wider research; the methods,
records and history live across the rest of the [research
section](/research).
> **[Interactive: ExperimentAuthors]** Rendered on the canonical page (link above); not shown in this markdown export.
## Every scored experiment, side by side

The full ledger: every named experiment that reached a board, across all
researchers, with the score it reached and how that run ended. Rows are
discovered from the pages themselves, so this stays in step with them; click a
column head to reorder. A score is marked with the convention it is under
(matched edges, or the stricter five-clue track), because a raw NNN/480 number
means different things under each.
> **[Interactive: ExperimentResultsTable]** Rendered on the canonical page (link above); not shown in this markdown export.
Not every result is a solver, and the table above is only the scored runs. To
browse the lab the other way, by what kind of result each page is (the analyses,
the theory, the measurements, and the dead ends kept as first-class negatives),
see the [by-contribution index](/research/lab/experiments/by-contribution).

## What counts as an experiment here

Some are original ideas; some faithfully reimplement a known community
technique to measure exactly what it buys. Each write-up says which it is, what
it attacked, where it stopped, and what it left open, so anyone can pick up
where it ended. And every result is reproducible: deterministic runs ship a
script and its exact output; searches that depend on randomness ship the same
script plus the board they found, loadable in the [viewer](/viewer) and
checkable edge by edge.

Every experiment also states the **hardware it ran on**, in a fixed spec card:
the cores, the machine, the time budget, and one derived number, core-hours,
that says what the run actually cost. It is mandatory, because a score means
nothing without the compute behind it. Where a run is directly comparable it
wears a **standardized bench** badge (one core, a fixed minute budget, restarted
from randomized corners); a bigger run is a **native run** that records its real
kit and the best score it reached. That way a from-scratch minute on one core
and a datacenter sweep on four hundred cores sit in the same table, each judged
against what it actually spent.

## Pages in this section

- [How the lab publishes](https://eternity2.dev/research/lab/experiments/methodology) — The editorial standard for this open notebook: how a piece of Eternity II research goes from unpublished work to a published page. What kind of contribution it is, whether it publishes, at what tier, and where it lives. One shared standard, built to scale to many authors.
- [Single-core benchmark](https://eternity2.dev/research/lab/experiments/single-core-benchmark) — Fifteen solvers, ours and our implementations of the community's two record backtrackers, each run once on ten corner-pinned variants of the official puzzle, single core, 60 seconds per run. The finding: node count is not score.
- [Raphaël Anjou's experiments](https://eternity2.dev/research/lab/experiments/raphael-anjou) — A notebook of Eternity II search experiments, organised into the shared engines they run on, the combination pipelines that chase the score, three studies that take one search paradigm apart a decision at a time, and exact endgame solves. Each has its idea, its best board, and the questions it left open. The best reaches 463 of 480.
- [Peter McGavin's engine](https://eternity2.dev/research/lab/experiments/peter-mcgavin) — Peter McGavin's own C backtracker, the fastest raw solver the community has measured. Fetched from the mailing list, built on an M1, and run on the real Eternity II. His code, his algorithm; run and written up here.
- [Joshua Blackwood's solver](https://eternity2.dev/research/lab/experiments/joshua-blackwood) — Joshua Blackwood's open-source C# solver, the one that found the standing 470 record. Built and run here as he published it, then with the five official clues pinned. His code, his algorithm; run and written up here.
- [Louis Verhaard's eii](https://eternity2.dev/research/lab/experiments/louis-verhaard) — Louis Verhaard's eii won the only prize the puzzle ever paid, but it shipped as a Windows binary with no source. What his method is, why the original will not run here, and where a faithful reimplementation of it lives.