WCCC
In the World Computer Chess Championship engines there are no limits on hardware that can be used. All games are played from the starting position, usage of opening books by engines is permitted (although Leela had only one move for white in its opening book and no opening book for black). Time control is 60 minutes plus 15s per move. Games are played over-the-board – engine operators make the moves.
2018 – Stockholm (24th WCCC)
Engine build: v0.15 running the “test-10” 20 × 256 network (net #42850).
Hardware: 8 × NVIDIA Tesla V100 GPUs for rounds 1-2, then 2 × GTX 1080 Ti for rounds 3-7.
Result: 7th place (2 points out of 7) in the 8-engine single-round-robin.
2022 - Vienna (26th WCCC)
Four years later, Lc0 returned to the WCCC as a title contender.
Engine build: v0.28 with the then-mainline T78 network (40 × 512 filters)
Hardware: 8 × NVIDIA A100 40 GB GPUs
Result: Lc0 tied Komodo dragon after the round robin, both engines with 5.5/8. Tie-breaks: four rapid games + Armageddon; Komodo Dragon won the Armageddon game, so Lc0 finished runner-up.
You can find some statistics here.
Side events at the 26th WCCC Alongside the main WCCC, the World Chess Software Championship and the World Computer Speed Chess Championship were also organized.
World Chess Software Championship is organized on the same hardware for all computers (AMD Ryzen 4750U with 32 GB of RAM) with a 45 minutes plus 15 seconds per move time control. Leela got 3rd place with 6.5/10 just half a point away from being tied for 1st despite running on a CPU.
In the World Computer Speed Chess Championship, Leela shared first with Ginkgo, and there were no tiebreaks due to a shortage of time.
2023 - Valencia (27th WCCC)
The 2023 edition clashed with TCEC Season 24 and major network development milestones. The team therefore decided not to field Lc0 in Valencia, concentrating resources on the new BT-series nets instead.
2024 - Santiago de Compostela (28th WCCC)
Lc0 was entered but subsequently withdrew when the organizers allowed ShashChess (essentially a copy of Stockfish) to participate without enforcing the usual originality rules. The decision and its rationale are explained in the blog post “Why we withdrew from WCCC”.