On July 13th, chess.com revealed Mystery as its new closed-source engine, Torch:
Announcing Torch: New #2 Chess Engine
Torch is a brand-new chess engine built from the ground up by top chess engine developers. The team is composed of: Andrew Grant (Ethereal), Finn Eggers & Kim Kåhre (Koivisto), Jay Honnold (Berserk), and Michael Whiteley & Dietrich Kappe (Dragon). Mark Lefler and Larry Kaufman have been advisors to the project.
Many on the team have long discussed joining forces to produce an engine capable of contending with the best out there. Through the support and funding of Chess.com, we have done exactly that. A single unified effort by our developers has allowed us to rapidly produce the new number-two engine according to Torch’s performance in the Chess.com Computer Chess Championship. Our goal is to be number one.
The development of Torch is supported by many open-source tools, including pytorch-nnue, Cutechess, and OpenBench. While Torch would not be as strong as it is today without these tools, the entire source code of Torch is an original effort with no code being used from any other engine.
Torch is not yet publicly available but will be made available to certain relevant third parties for ratings. It will also be available through Chess.com’s analysis in the future. The team hopes to bring new ideas to the engine to allow greater insights to be delivered to the chess community. Chess is an infinitely fascinating game, and our goal is to push further into the depths.