Triumviratus 8.0 20261004 - new version chess engine

Triumviratus is a strong, UCI-compliant chess engine written in C++. 

Author: Francesco (fraTorsello)   Rating Chess Engines Diary CEDR=3849

Triumviratus what's new?

This is a pre-release for testing. It replaces the pre-release of 1 October: the network is the same
(Consilium), the search is new.

What is new

• Search restructured. Nearly all of the search's structures were already in the engine, but disordered and
  clogged by parameters and tests accumulated one at a time since version 5.0. After studying the searches of
  Stockfish and Reckless, the search was reorganised following the structure of Stockfish 19's search (GPLv3).
  It is Triumviratus' own code, with our own data structures, move generation, evaluation and network.
  
• Search parameters re-tuned on our network. 51 parameters re-tuned by SPSA at 20+0.2 and built in.
• Passed-pawn pushes in endgames, a technique of our own: with little material left, a push of a passed pawn
  to the 6th or 7th rank is reduced less and never pruned. Our network sees passed pawns through its own
  PassedPawns input block.
• Faster accumulator refresh when a capture moves the position into another phase of the network (another of
  Consilium's four experts): only the expert's part is rebuilt, the rest is reused. Same moves, slightly faster.

Unchanged from 1 October: the network, ponder, Chess960, the UCI options.

Strength

Opponent	TC	Games	Elo
8.0 of 3 October, previous search	20+0.2	694	+85.8 ± 12.8
8.0 of 3 October, previous search	10+0.1	1,390	+61.6 ± 10.2 (before the SPSA)

Triumviratus is an exciting and fast-evolving chess engine that, as 1.10.2026, reached a CEDR rating of 3849. Silnik is currently competing in the 3rd League and holds the top spot after completing 30% of the season’s matches.

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