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Dolphin 2.1

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@aiagentvn aiagentvn released this 11 Oct 07:48
v2.1.0
821fd6d

Dolphin 2.1 brings a stronger self-trained network and a self-contained Windows build that needs no .NET installation.

Download

File Use it if
Dolphin-2.1.0-windows-x64.zip Recommended. Self-contained: includes its own .NET runtime, nothing to install. Keep all five files of the folder together.
Dolphin-2.1.0-windows-x64-requires-dotnet.zip You already have the .NET Runtime 5.0 or newer and want the small package. Keep the four files Dolphin2.exe, Dolphin2.dll, Dolphin2.deps.json, Dolphin2.runtimeconfig.json together.

Unzip and load Dolphin2.exe into your GUI as a UCI engine. The network is embedded in the program. Requires Windows on a 64-bit (x64) CPU; CPUs with AVX2 use a faster NNUE path. Each package contains a README.txt with setup and troubleshooting notes.

What's new

  • New network, trained from scratch on about 44 million positions from Dolphin's own self-play games (five generations of data, each played with the best network available at the time). Same architecture as 2.0: 768 → 384×2 (SCReLU) → 8 output buckets.
  • Self-contained Windows package: no .NET installation needed.
  • Engine name now reports Dolphin 2.1 NNUE.
  • Hardening: stricter validation of moves taken from the transposition table, and PV bookkeeping is reset in every quiescence node. Neither changes the search (the bench node count is identical).
  • README: download guide and troubleshooting section.

Testing

All games with cutechess-cli 1.5.1 on an i7-11800H, using the release packages as downloaded, against Dolphin 2.0.0 (except the last row), openings from tools/openings8.epd.

Time control Settings Games Result (W-L-D) Elo vs 2.0
10+0.1 1 thread, 64 MB 1000 352 - 215 - 433 +47.9 ± 16.2
40 moves / 30 s 1 thread, 64 MB 100 36 - 20 - 44 +56.1 ± 51.4
40 moves / 30 s (final packages) 1 thread, 64 MB 200 69 - 25 - 106 +77.7 ± 32.9
2 min + 1 s 1 thread, 128 MB 40 14 - 5 - 21 +79.5 ± 75.1
10+0.1 4 threads, 1 GB (both engines) 20 4 - 5 - 11 too few games
5+0.05, engine restarted every game both 2.1 packages against each other 100 29 - 22 - 49 (same engine)

1460 games in total: no time losses, no crashes, no illegal moves. The rows without a note were played with the release candidate, which differs from the final build only by the two hardening checks above (identical bench node count). In one of those games cutechess reported a single PV line that continued one move past a checkmate (display only, the played moves were legal). Its cause has not been confirmed yet; the PV hardening addresses the most likely path, and the 200 games with the final packages produced no warnings, which is encouraging but not proof. Reports of any remaining PV warnings are welcome.

Verify

  • Dolphin2.exe perft 5 must print Nodes searched: 4865609
  • Dolphin2.exe bench must print Nodes searched : 3292308
  • SHA-256:
    • Dolphin-2.1.0-windows-x64.zip: 494B28BDA2216D0CBBABE06A58C4F8013082A39B01F34D3C40001B18CA7EFE0C
    • Dolphin-2.1.0-windows-x64-requires-dotnet.zip: 59B1A928DF8A9FC33879EE4DA8E2348E27B8C8170A94B53FF6A175D7B159FEAB

Build from source

git clone https://github.com/aiagentvn/dolphin.git
cd dolphin
dotnet build -c Release

The binaries in this release were built from the source at this tag.

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