Revolution - Revolution is a free, open-source UCI chess engine derived from Stockfish. Jorge Ruiz Centelles, with credit to ChatGPT, modifies and extends the code to explore new concepts. The engine implements cutting-edge search algorithms combined with neural network evaluation. Derived from fundamental chess programming principles, Revolution analyzes positions through parallelized alpha-beta search enhanced with null-move pruning and late move reductions.
As a UCI-compliant engine, Revolution operates through standard chess interfaces without an integrated graphical interface. Users must employ compatible chess GUIs (Arena, Scid vs PC, etc.) for board visualization and move input. Consult your GUI documentation for implementation details.
What changed in Revolution-5.20-040426 compared with Revolution-5.10-090326
The NNUE architecture was updated to the official SFNNv14 semantics: the release ports the upstream Stockfish patch corresponding to the SFNNv14 transition, rather than merely renaming a net file. In practical terms, this means the feature logic was brought into line with the newer Stockfish NNUE architecture path.
Default NNUE network files were replaced: the previous default filenames were retired and the current release now points to nn-7bf13f9655c8.nnue for the big net and nn-47fc8b7fff06.nnue for the small net. This change was synchronised across the relevant naming authorities so that build and runtime defaults remain aligned.
FullThreats was expanded from 60144 to 60720 dimensions: the feature space now reflects the extended threat encoding associated with the SFNNv14 patch line. This is a material internal evaluation change, not a superficial packaging adjustment.
Blocked-pawn threat features were added: the release introduces pawn_single_push_bb() and PawnPushOrAttacks, and uses them in the threat-generation path so that pawn pushes blocked by an opposing pawn are represented in the NNUE feature logic.
Position::update_piece_threats() was updated in a controlled way: the patch was ported manually and narrowly, without replacing the whole file. This keeps the Revolution derivative line aligned with the intended upstream NNUE semantics while avoiding unrelated interference with custom project code.
The release now uses a deterministic hyphenated ISA identity at GUI level: unlike the older mixed name/version presentation, the current line exposes a single consistent engine identity such as Revolution-5.20-040426-avx2, Revolution-5.20-040426-bmi2 or Revolution-5.20-040426-FMA3. This matters for Fritz, Cute Chess and tournament telemetry because engine discovery becomes cleaner and less ambiguous.
Explicit FMA3 release support was retained and validated: this release does not leave FMA3 as a nominal or accidental target. The build and identity path for x86-64-fma3 was audited so that the final engine can present itself correctly as Revolution-5.20-040426-FMA3, which is especially relevant for Zen 4-class deployment.
An avx512cl alias line was added for release clarity: the current build logic preserves the existing AVX-512 Ice Lake / Zen 4 feature path, while also exposing a first-class avx512cl release suffix for packaging and GUI identification.
The intervention remained deliberately narrow in scope: the release does not claim a broad rewrite of search, does not redesign the experience layer, and does not introduce unrelated algorithmic changes outside the patch and naming scope. It should therefore be read as a technical evaluation-and-packaging release rather than as a speculative engine fork.
Revolution 4.90 210226 vs other engines:
| Raid 6.0 | 13/26 | +0 | 26 games |
| Hlamnick 200226 | 12.5/26 | -1 | 26 games |
| Artemis 27TR PrO | 12.5/26 | -1 | 26 games |
| Stockfish 18 JA | 11/22 | +0 | 22 games |
| DON dev-20260222 | 10.5/20 | +1 | 20 games |
| Leptir Testpilot | 10.5/20 | +1 | 20 games |
| DarkSeid 10.3 SE | 9.5/18 | +1 | 18 games |
| SF-PRO2 29.01.2026 | 9.5/18 | +1 | 18 games |
| Stockfish dev-20260218 | 9/18 | +0 | 18 games |
| ShashChess 40 | 9/18 | +0 | 18 games |
| Brainlearn 31 | 8.5/18 | -1 | 18 games |
| StockfishMZ 121225 | 8.5/18 | -1 | 18 games |
| CorChess 20260212 | 8.5/18 | -1 | 18 games |
| Kookaburra 3.11 | 7/14 | +0 | 14 games |
| Halogen 16.0.0 | 7/10 | +4 | 10 games |
| SF-POLY 160226 | 4.5/8 | +1 | 8 games |
| HypnoS EN 2.0 | 4.5/8 | +1 | 8 games |
| JigSaw 8.0 | 4/8 | +0 | 8 games |
| Stockfish 18 | 4/8 | +0 | 8 games |
| DarkSeid 10.2 SE | 4/8 | +0 | 8 games |
| Sky Mini MPV | 3.5/8 | -1 | 8 games |
Revolution 5.20 040426 - download
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