Stockfish claims its 19th TCEC title, defeating Reckless in the Superfinal
Stockfish has done it again. The open-source chess engine clinched the Top Chess Engine Championship Season 29 Grand Champion title after a dominant 100-game Superfinal against the surging challenger Reckless, completing another masterclass in computer chess. The result marks Stockfish’s 19th TCEC championship overall and its 12th consecutive season title.
Official website of the Top Chess Engine Championship
TCEC Season 29 Superfinal
Throughout the broader Season 29 tournament, the competition was notably fierce. Engines such as Torch, which joined the field for the first time, and several other Premier Division monsters such as Lc0, Plentychess, and Integral, pushed hard for Superfinal qualification, reflecting the accelerating pace of development across the computer chess ecosystem.
For years, the top tier of computer chess has been defined by a familiar rivalry: Stockfish versus Leela Chess Zero (see last season Stockfish vs Lc0 Season 28 Superfinal). But in a dramatic and unexpected turn, that era was disrupted. For the first time in many seasons, the prestigious Top Chess Engine Championship Superfinal did not feature the long-standing clash between those two giants. Instead, a new contender, Reckless, has surged into the spotlight. A relative newcomer that had turned heads throughout the Season 29 leagues with its aggressive, unconventional playing style, Reckeless pushed Stockfish harder in the early game pairs than many observers expected.
However, as the tournament progressed, Stockfish established its dominance and step by step increased the lead. The final score of the match was a dominant 59.0 – 41.0 in favor of the reigning champion.
Replay: TCEC Season 29 Superfinal Interview: Arseniy Surkov, author of Reckless
TCEC Grand Champion (Superfinal/Leagues Season)
| Season | Date | Stockfish Version | Score | Runner-up |
|---|---|---|---|---|
| Season 6 | Feb–May 2014 | Stockfish 170514 (1st title) | +13 =45 -6 | Komodo 7x |
| Season 9 | May–Dec 2016 | Stockfish 8 (2nd) | +17 =75 -8 | Houdini 5 |
| Season 11 | Jan–Apr 2018 | Stockfish 260318 (3rd) | +20 =78 -2 | Houdini 6.03 |
| Season 12 | Apr–Jul 2018 | Stockfish 180614 (4th) | +29 =62 -9 | Komodo 12.1.1 |
| Season 13 | Aug–Nov 2018 | Stockfish 18102108 (5th) | +16 =78 -6 | Komodo 2155.00 |
| Season 14 | Nov 2018–Feb 2019 | Stockfish 190203 (6th) | +10 =81 -9 | LCZero v0.20.2 |
| Season 16 | Jul–Oct 2019 | Stockfish 19092522 (7th) | +14 =81 -5 | AllieStein v0.5 |
| Season 18 | May–Jul 2020 | Stockfish 202006170741 (8th) | +23 =61 -16 | LCZero v0.25.1 |
| Season 19 | Aug–Oct 2020 | Stockfish 202009282242 (9th) | +18 =73 -9 | LCZero v0.26.3 |
| Season 20 | Dec 2020–Feb 2021 | Stockfish 20210113 (10th) | +14 =78 -8 | LCZero 0.27.0d |
| Season 21 | May–Aug 2021 | Stockfish 14_202107131735 (11th) | +19 =74 -7 | LCZero 0.28 |
| Season 22 | Jan–Apr 2022 | Stockfish dev15_20220401 (12th) | +28 =63 -9 | KomodoDragon 2894.00 |
| Season 23 | Aug–Nov 2022 | Stockfish dev16_20221027 (13th) | +27 =63 -10 | LCZero 0.30 |
| Season 24 | Feb–Apr 2023 | Stockfish dev-20230409 (14th) | +20 =64 -16 | LCZero 0.30 |
| Season 25 | Aug–Oct 2023 | Stockfish dev-20231010 (15th) | +27 =50 -23 | LCZero 0.31 |
| Season 26 | May–Jun 2024 | Stockfish dev-20240513 (16th) | +31 =52 -17 | LCZero 0.31 |
| Season 27 | Oct 2024–Jan 2025 | Stockfish dev-20241208 (17th) | +35 =47 -18 | LCZero 0.31 |
| Season 28 | Jun–Sep 2025 | Stockfish dev-20250824 (18th) | +36 =43 -21 | LCZero 0.33 |
| Season 29 | Jan–Apr 2026 | Stockfish dev-20260318 (19th) | +41 =36 -23 | Reckless 0.10.0-dev-b5462f11 |
Stockfish has amassed 19 Grand Champion titles, 12 Cup titles, 5 Swiss titles, 5 FRC titles, 2 DFRC titles, 4 FRD titles, making it by far the most decorated engine in TCEC history.
TCEC Cup
| Cup | Date | Stockfish Version | Score | Runner-up |
|---|---|---|---|---|
| Cup 1 | Oct 2018 | Stockfish 270918 (1st) | +1 =7 -0 | Houdini 6.03 |
| Cup 4 | Oct 2019 | Stockfish 19100908 (2nd) | +1 =7 -0 | LCZero v0.22.0 |
| Cup 5 | Apr 2020 | Stockfish 202004181536 (3rd) | +1 =3 -0 | LCZero v0.24 |
| Cup 7 | Nov 2020 | Stockfish 2020102823 (4th) | +1 =3 -0 | LCZero v0.26.3 |
| Cup 8 | Feb 2021 | Stockfish 202102202249 (5th) | +1 =7 -0 | LCZero 0.27.0 |
| Cup 9 | Oct 2021 | Stockfish dev15_20211015 (6th) | +1 =3 -0 | LCZero 0.28 |
| Cup 10 | May 2022 | Stockfish dev16_2022051413 (7th) | +2 =9 -1 | KomodoDragon 3 |
| Cup 12 | Jul 2023 | Stockfish dev-20230713 (8th) | +10 =9 -9 | LCZero 0.31 |
| Cup 13 | Mar 2024 | Stockfish dev-20240217 (9th) | +4 =17 -1 | LCZero 0.31 |
| Cup 14 | Oct 2024 | Stockfish dev-20240928 (10th) | +12 =13 -11 | LCZero 0.31 |
| Cup 15 | Jun 2025 | Stockfish dev-20250602 (11th) | +6 =13 -3 | LCZero 0.31 |
| Cup 16 | Jan 2026 | Stockfish dev-20260101 (12th) | +7 =12 -3 | LCZero 0.33 |
TCEC Swiss
| Swiss | Date | Stockfish Version | Runner-up |
|---|---|---|---|
| Swiss 3 | May–Jul 2022 | Stockfish dev16_20220521 (1st) | LCZero 0.30 |
| Swiss 4 | Jan–Feb 2023 | Stockfish dev-20230114 (2nd) | LCZero 0.30 / KomodoDragon 3.2 |
| Swiss 5 | Jun–Jul 2023 | Stockfish dev-20230614 (3rd) | LCZero 0.31 |
| Swiss 8 | Apr–Jun 2025 | Stockfish dev-20250513 (4th) | LCZero 0.31 |
| Swiss 9 | Nov–Dec 2025 | Stockfish dev-20251203 (5th) | LCZero 0.33 |
TCEC FRC (Fischer Random Chess)
| FRC | Date | Stockfish Version | Score | Runner-up |
|---|---|---|---|---|
| FRC 1 | Oct–Nov 2019 | Stockfish 191107 (1st) | +10 =10 -0 | AllieStein v0.5 |
| FRC 2 | Nov 2020 | Stockfish 202011101829 (2nd) | +8 =42 -0 | LCZero v0.26.3 |
| FRC 4 | Dec 2021–Jan 2022 | Stockfish dev15_2021121915 (3rd) | +13 =28 -9 | LCZero 0.29 |
| FRC 5 | Jul 2022 | Stockfish dev16_20220705 (4th) | +17 =20 -13 | LCZero 0.30 |
| FRC 6 | May 2023 | Stockfish dev-20230507 (5th) | +15 =23 -12 | LCZero 0.31 |
TCEC DFRC (Double Fischer Random Chess)
| DFRC | Date | Stockfish Version | Score | Runner-up |
|---|---|---|---|---|
| DFRC 1 | Jul–Aug 2022 | Stockfish dev16_202207131801 (1st) | +18 =23 -9 | LCZero 0.30 |
| DFRC 2 | May–Jun 2023 | Stockfish dev-20230528 (2nd) | +10 =33 -7 | LCZero 0.31 |
TCEC FRD (Fischer Random Double)
| FRD | Date | Stockfish Version | Score | Runner-up |
|---|---|---|---|---|
| FRD 1 | Nov–Dec 2023 | Stockfish dev-20231116 (1st) | +11 =29 -10 | LCZero 0.31 |
| FRD 2 | Jun–Jul 2024 | Stockfish dev-20240612 (2nd) | +20 =16 -14 | LCZero 0.31 |
| FRD 3 | Feb 2025 | Stockfish dev-20250126 (3rd) | +13 =25 -12 | LCZero 0.31 |
| FRD 4 | Sep–Oct 2025 | Stockfish dev-20250913 (4th) | +18 =18 -14 | LCZero 0.33 |