Historical Stockfish evaluation network architectures
This document records the complete history of Stockfish's NNUE evaluation network architectures. For NNUE principles, implementation, training, and architectural explanations, see NNUE.
Table of contents
- "SFNNv17" architecture
- "SFNNv16" architecture
- "SFNNv15" architecture
- "SFNNv14.1" architecture
- "SFNNv14" architecture
- "SFNNv13" architecture
- "SFNNv12" architecture
- "SFNNv11" architecture
- "SFNNv10" architecture
- "SFNNv9" architecture
- "SFNNv8" architecture
- "SFNNv7" architecture
- "SFNNv6" architecture
- "SFNNv5" architecture
- "SFNNv4" architecture
- "SFNNv3" architecture
- "SFNNv2" architecture
- "SFNNv1" architecture
"SFNNv17" architecture
Removed the direct PSQT-like connection.
2026-09-30 - *
Commit a17c0ce28d5a4cc40e3f2d0e8892cb1cb4234730
"SFNNv16" architecture
Added PP_3Wide features.
2026-07-20 - 2026-09-30
Commit f4bcd40409f94bd397a083c5d6243bac6dcc6d85
"SFNNv15" architecture
2026-07-03 - 2026-07-20
Commit e33bb26ee7320629dd9114a936a38e6f4d43d52a
"SFNNv14.1" architecture
Same as "SFNNv14" with updated fixed-point quantization.
2026-05-26 - 2026-07-03
Commit 313ea4ab0410872e99f0668c74edc7e49e9a0b6a
"SFNNv14" architecture
Added opposed-pawn features to FullThreats.
2026-04-02 - 2026-05-26
Commit 5eeca7392ee90b7a43da69e647e3d596e42992fd
"SFNNv13" architecture
Same as "SFNNv12" with L2 size increased to 32.
2026-02-18 - 2026-04-02
Commit a6d055d7e27ab3e29a42e8b94215102824760057
"SFNNv12" architecture
Removed king to piece threats from FullThreats.
2026-02-12 - 2026-02-18
Commit 83e42045a62c3690a6ee29862679403ea1644728
"SFNNv11" architecture
Removed piece to king threats from FullThreats.
2026-02-04 - 2026-02-12
Commit fac506bdf3f0ed46fd0823ff1ed592824f91aa5a
"SFNNv10" architecture
Added FullThreats input features, L1 size reduced to 1024, and used 255 as the feature transformer quantization scale.
2025-11-12 - 2026-02-04
Commit 8e5392d79a36aba5b997cf6fb590937e3e624e80
"SFNNv9" architecture
Same as "SFNNv8" with L1 size increased to 3072.
2024-04-01 - 2025-11-12
Commit 0716b845fdef8a20102b07eaec074b8da8162523
"SFNNv8" architecture
Same as "SFNNv7" with L1 size increased to 2560.
2023-09-22 - 2024-04-01
Commit 782c32223583d7774770fc56e50bd88aae35cd1a
"SFNNv7" architecture
Same as "SFNNv6" with L1 size increased to 2048.
2023-07-01 - 2023-09-22
Commit 915532181f11812c80ef0b57bc018de4ea2155ec
"SFNNv6" architecture
Same as "SFNNv5" with L1 size increased from 1024 to 1536.
2023-05-31 - 2023-07-01
Commit c1fff71650e2f8bf5a2d63bdc043161cdfe8e460
"SFNNv5" architecture
2022-05-14 - 2023-05-31
Commit c079acc26f93acc2eda08c7218c60559854f52f0
"SFNNv4" architecture
2022-02-10 - 2022-05-14
Commit cb9c2594fcedc881ae8f8bfbfdf130cf89840e4c
"SFNNv3" architecture
2021-08-15 - 2022-02-10
Commit d61d38586ee35fd4d93445eb547e4af27cc86e6b
"SFNNv2" architecture
2021-05-18 - 2021-08-15
Commit e8d64af1230fdac65bb0da246df3e7abe82e0838
"SFNNv1" architecture
Also known as "Stockfish 12 architecture".
2020-08-06 - 2021-05-18
Commit 84f3e867903f62480c33243dd0ecbffd342796fc
