Top Chess Engine Championship (TCEC), the world’s premier championship for computer chess, started its new season with the highly anticipated TCEC Swiss 8 tournament, featuring 44 of the world’s most advanced chess engines. This event surpassed the record set by last season’s Swiss 7, cementing its status as the strongest chess championship ever. With a lineup of elite engines, cutting-edge hardware (record: see the press release), and a global audience of chess enthusiasts, TCEC Swiss 8 promises to deliver a unique show 24/7 over the next months. Follow TCEC Swiss 8 live: Official website / TCEC Chess TV / Lichess / Chessdom live

Stockfish is sole leader after 16 games

After 8 double rounds, or 16 games, Stockfish is the sole leader of TCEC Swiss 8. In R8 Stockfish scored 1,5-0,5 vs Ethreal, while the surprise of the season Integral managed to hold Leela to a 1-1 draw. This was enough for Stockfish to collect 11,0/16, half a point ahead of Leela and 1,5 points ahead of Berserk, KomodoDragon, Integral, and PlentyChess.

Next round will see Stockfish – PlentyChess and Leela Chess Zero – Seer

Top Chess Engine Championship (TCEC), the world’s premier championship for computer chess, started its new season with the highly anticipated TCEC Swiss 8 tournament, featuring 44 of the world’s most advanced chess engines. This event surpassed the record set by last season’s Swiss 7, cementing its status as the strongest chess championship ever. With a lineup of elite engines, cutting-edge hardware (record: see the press release), and a global audience of chess enthusiasts, TCEC Swiss 8 promises to deliver a unique show 24/7 over the next months. Follow TCEC Swiss 8 live: Official website / TCEC Chess TV / Lichess / Chessdom live

After 7 double rounds of TCEC Swiss 8, Stockfish and Leela share the lead with 9,5/14 each. Leela won its match against Boot (replay here), while Stockfish defeated the surprising early leader KomodoDragon, overtaking it in the standings

TCEC Swiss 8 standings after 14 games

Top Chess Engine Championship (TCEC), the world’s premier championship for computer chess, launched its new season with the highly anticipated TCEC Swiss 8 tournament on May 16, 2025, at 19:00 CEST. Featuring 44 of the world’s most advanced chess engines, this event is poised to surpass the record set by last season’s Swiss 7, cementing its status as the strongest chess championship ever. With a lineup of elite engines, cutting-edge hardware, and a global audience of chess enthusiasts, TCEC Swiss 8 promises to deliver a unique show 24/7 over the next months. Follow TCEC Swiss 8 live: Official website / TCEC Chess TV / Lichess / Chessdom live

After 4 double rounds (8 games) there is a surprising leader at TCEC Swiss 8. KomodoDragon leads with 5,5/8, ahead of Lc0, Stockfish, Obsidian, Horsie, Berserk, PlentyChess, Caissa, Stoofvless, Ceres, and Ethereal, all with 5,0/8.

Standings after 4 double rounds

Leela Chess Zero close to crossing the 3700 elo mark

Round 1 of TCEC Swiss 8 is now in the history books, with a second engine approaching 3700 elo mark. After Stockfish became the first engine to cross 3700 this month of April, now Leela Chess Zero is close to joining the 3700 elo club. Leela defeated Ethereal (elo 3617) with the score 1,5-0,5 in their TCEC Swiss 8 mini match. The current elo of Leela Chess Zero is 3699

Replay all the games of round 1 here

No engine achieves double victory in round 1

As per the rules, each round the opponents play the same opening once as white and once as black. A total of 15 engines won their mini matches in round 1. Yet, no engine achieved to win the mini match with a perfect 2,0/2 score. Here are the standings after the first round.

Patricia (3357) – 1.5
KomodoDragon (3620) – 1.5
Stockfish (3733) – 1.5
LCZero (3697) – 1.5
PlentyChess (3551) – 1.5
Starzix (3482) – 1.5
Weiss (3383) – 1.5
Velvet (3522) – 1.5
Berserk (3650) – 1.5
Obsidian (3644) – 1.5
Integral (3428) – 1.5
Ginkgo (3543) – 1.5
Stormphrax (3543) – 1.5
Tucano (3384) – 1.5
Texel (3380) – 1.5

sirius (3322) – 1
Booot (3454) – 1
BlackMarlin (3500) – 1
Uralochka (3540) – 1
STRO4K (2914) – 1
Reckless (3460) – 1
ScorpioNN (3411) – 1
rofChade (3578) – 1
Stoofvlees (3556) – 1
Horsie (3508) – 1
Viridithas (3578) – 1
Clover (3535) – 1
Renegade (3438) – 1
Stash (3344) – 1

Ethereal (3617) – 0.5
Lynx (3226) – 0.5
ice4 (3140) – 0.5
DeepSjeng (3451) – 0.5
Igel (3526) – 0.5
Minic (3456) – 0.5
Caissa (3598) – 0.5
Ceres (3628) – 0.5
Seer (3552) – 0.5
Revenge (3522) – 0.5
ChessFighter (3206) – 0.5
Altair (3439) – 0.5
Arasan (3481) – 0.5
RubiChess (3600) – 0.5
Princhess (3169) – 0.5

Follow Swiss 8 live: Official website / TCEC Chess TV / Innovations in TCEC / Live on Chessdom

Top Chess Engine Championship Swiss 8 participants

Top Chess Engine Championship (TCEC), the world’s premier championship for computer chess, is set to launch its new season with the highly anticipated TCEC Swiss 8 tournament on May 16, 2025, at 19:00 CEST. Featuring 44 of the world’s most advanced chess engines, this event is poised to surpass the record set by last season’s Swiss 7, cementing its status as the strongest chess championship ever. With a lineup of elite engines, cutting-edge hardware, and a global audience of chess enthusiasts, TCEC Swiss 8 promises to deliver a unique show 24/7 over the next months. Follow TCEC Swiss 8 live: Official website / TCEC Chess TV / Lichess / Chessdom live

Hardware boost for chess engines at TCEC aka Kittenware

With high confidence we can say that TCEC has the best hardware setup for chess ever, and you can enjoy it live during TCEC Season 28 and TCEC Swiss 8 thanks to the sponsorship of Kittenkaboodle.

Kanchess comments, “The brand new Kittenware truly belongs in TCEC as most serious top chess engine competition, and is an awesome donation! Can’t wait to see which engines will show how to use this monster hardware with two separate boxes more to their advantage and add some substantial elo” Aloril adds, “Best effort was truly done for both CPU and GPU engines by Kittenkaboodle.“

The GPU boost, benefiting NN engines is the following:

Current new hardware, sponsored by Kittenkaboodle: 8x RTX 5090 (32GB):

• Total memory: 256GB (32GB x 8).
• Total CUDA cores: ~174,080
• Total Tensor cores: ~5,440
• Total power consumption: ~3,600W (450W x 8)

Former hardware, sponsored by Noobpwnftw: 2x A100-PCIE-40GB:

• Total memory: 80GB (40GB x 2).
• Total CUDA cores: 13,824.
• Total Tensor cores: 864.
• Total power consumption: ~500W.

Traditional CPU engines will also enjoy a boost

Current new hardware, sponsored by Kittenkaboodle: AMD EPYC 9754 (2x):

• Type: Server-grade CPU, 4th Gen EPYC (Bergamo, Zen 4c, 5nm).
• Cores/Threads: 128 cores/256 threads per CPU, total 256 cores/512 threads.
• Clock Speed: 2.25 GHz base, 3.1 GHz boost (lower boost due to high core count).
• Cache: 256 MB L3 cache per CPU (512 MB total).
• Performance: ~180,000–200,000 PassMark score per CPU (estimated, ~360,000–400,000 total).

Former hardware, sponsored by Noobpwnftw: Intel Xeon 6230R (2x):

• Type: Server-grade CPU, 3rd Gen Scalable Xeon (Cascade Lake Refresh, 14nm).
• Cores/Threads: 26 cores/52 threads per CPU, total 52 cores/104 threads.
• Clock Speed: 2.1 GHz base, 4.0 GHz turbo.
• Cache: 35.75 MB L3 cache per CPU (71.5 MB total).
• Performance: ~40,000 PassMark score per CPU (estimated, ~80,000 total).

Participants and ELO records

In the three years period between Swiss 1 and Swiss 7, the average ELO of the top 10 participants has increased by 60 points. Now in under 12 months we see another increase of 60 points! In this TCEC Swiss 8 for the first time the chess world will see a 3700+ engine in action, in a top 10 field that exceeds 3621 average ELO!

Stockfish (Elo: 3728): The open-source juggernaut and reigning TCEC Grand Champion, Stockfish has dominated the last seasons, winning the Leagues, Fischer Random, and Cup events. It has just set an unseen rating record and is coming for the only title it lacked last season – the Swiss

LCZero (Elo: 3693): The neural network-based engine, built on the principles of AlphaZero, is coming to TCEC Swiss as defending champion, while aiming to cross the 3700 elo mark during the event

Berserk (Elo: 3646): A rising star in the computer chess world, Berserk has climbed the rankings with its aggressive play and robust performance, making one of the dark horses in Swiss 8.

Obsidian (Elo: 3637): Authored by Gabriele Lombardo who is still U18, Obsidian aims to get minimum a medal at Swiss 8

Ceres (Elo: 3624): A newcomer to the elite ranks in the past season, Ceres has impressed with its performance and is expected to challenge the established giants.

KomodoDragon (Elo: 3615): A veteran engine with TCEC titles in Seasons 5, 7, and 8, KomodoDragon remains a formidable competitor, despite not being actively updated. Once part of the big 3, now KomodoDragon is trying to stay among the best.

Ethereal (Elo: 3613): A consistent performer, Ethereal brings a balanced approach to the board, capable of upsetting higher-rated opponents, while gaining strength every season

Caissa (Elo: 3591): A newer engine that has shown promise in recent seasons, Caissa is poised to make waves in the computer chess world

RubiChess (Elo: 3591): With a solid track record, RubiChess is a reliable contender that can take valuable points from the favorites

Viridithas (Elo: 3570): A lesser-known but rapidly improving engine, Viridithas adds unpredictability to the mix with its unique playing style

Stay tuned for the full list of participants.

More about the Top Chess Engine Championship

TCEC seasons are divided into multiple events, including the traditional Leagues, a knockout Cup, a Fischer Random tournament, and the Swiss tournament.

Since its inception in 2010, TCEC has been the premier platform for pitting the world’s top chess engines against one another in long time-control matches on high-end hardware. Originally known as the Thoresen Chess Engines Competition, TCEC was founded by Martin Thoresen and has been organized by Chessdom since Season 7. The tournament’s reputation as the “Unofficial World Computer Chess Championship” stems from its rigorous format, elite participant lineup, and commitment to showcasing the highest level of computer chess.

TCEC started with a bang – the newcomer Caissa has taken the sole lead in the event after round 2! Caissa won a Sicilian game against KomodoDragon and a King’s Indian against Seer to score 2,0/2 and jump into sole first. Caissa is closely followed by Stockfish with 1,5/2. The defending champion drew its game vs KomodoDragon and defeated Obisidian. The third position is shared by Ethereal, Berserk, and Lc0 with 1,0/2.

More about Caissa chess engine

Caissa is a strong chess engine written from scratch in C++ by Michał Witanowski (Witek902). It employs a custom efficiently-updated neural network trained with self-play games using a custom trainer. It supports (D)FRC and endgame tablebases. In development since early 2021. TCEC debut S25 Swiss5 & EL. Best score for the engine is 9th position (S26 L1) and this year it has a guaranteed 8th or more, improving on the standings. Official website: Github.com/Witek902/Caissa

Currently TCEC is in its season 27 and it is heading to its key moment, the Premier Division. There Stockfish, Leela Chess Zero, Berserk, KomodoDragon, and Seer will be joined by two ascending engines from the ongoing qualification, named League 1. There, after 23 rounds things are more surprising than ever! Seasoned fighters and medalists in TCEC events Rubichess, Rofchade, or Stoofvlees have practically no chance of joining the Premier Division. Rather, we will see Obsidian, Caissa, or Ceres enter the race for the first time.

Obsidian is currently the engine leading League 1, just past the halfway mark, with 15,5/23. The engine, written by 16 year old Gabriele Lombardo, is literally disrupting the field. While most pundits expected Ceres to win L1 and challenge the top positions in the TCEC Premier Division, it is the new version of Obsidian that shows what it takes to question the dominance of the top engines. It is now 0,5 points ahead of Caissa and a point ahead of Ceres. Only two of those engines will qualify for the Premier Division, but surely they will gun for medal positions and change a status quo in computer chess that we have seen for a decade.

Follow the TCEC championship live here

TCEC L1 standings

1. Obsidian 15,5/23
2. Caissa 15,0/23
3. Ceres 14,5/23
4. RubiChess 12,5/23
5. RofChade 11,0/23
6. Stoofvlees 10,5/23
7. Uralochka 10,5/23
8. Igel 10,0/23
9. PlentyChess 10,0/23
10. Viridithas 10,0/23
11. Revenge 9,5/23
12. Devre 9,0/23

It’s a lovely opsitional squeeze from Leela starting from an opening position that suits its style down to the ground. An early (book) advance of the g-pawn in a Budapest Gambit secures Leela the f4-square for its pieces in perpetuity. Leela uses this asset beautifully to extract more and more concessions from Ethereal culminating in a tale of 2 rook’s pawns in a 2 bishops against 2 knights endgame: Leela’s rook’s pawn on h6 is invulnerable and crippling, Ethereal’s a4-pawn is weak and open to attack! The game is viewable here: https://tcec-chess.com/#div=sw&game=396&season=27

More: Leela Chess Zero wins TCEC Swiss 7 / Leela-Obsidian TCEC Swiss 7 (video) / Slicing and dicing the Budapest: Alekhine’s 4.e4… with a twist!

In an impressive display Leela Chess Zero won nine of the eleven matches. Particularly impressive were the wins against the top 10 engines Berserk, Obsidian, Ethereal, KomodoDragon, and Caissa. The other medalists – Stockfish and Ceres – managed to hold Leela to equal score, but dropped points against lower rated opposition.

Follow TCEC live: Official website / TCEC Chess TV / Lichess / Chessdom live More: Interview with Gabriele Lombardo from Obsidian

TCEC Swiss 7 final standings

1. Leela Chess Zero 15,5/22
2. Stockfish 14,5/22
3. Ceres 13,5/22
4. Berserk 12,5/22
5. Revenge 12,5/22
6. Obsidian 12,0/22
7. Ethereal 12,0/22
8. KomodoDragon 12,0/22
9. Caissa 12,0/22
10. Viridithas 12,0/22

Full standings here

Next: TCEC Cup

Next up on the TCEC season is the TCEC Cup – the knockout competition featuring the top 32 engines from the Swiss. This will be the 14th edition of the Cup, with Stockfish entering as defending champion.