Coliseum v3.9.0 “Trial by Combat”

Coliseum v3.9.0

Coliseum is now a proper engine-testing tool: SPRT tests, adjudication, fixed depth and node limits, opening suites from EPD and PGN files, WinBoard engines, and a Linux version. It also has a new look, an opening book manager, and a sidebar you can arrange yourself.

New look: the Coliseum theme

• Roman colours: Coliseum now looks like its namesake, with warm travertine stone, bronze and dark stone. The original neon green is still there as the Matrix theme.
• Easier to read: the new default board is light and dark stone with classic white and black pieces, which are told apart by brightness rather than red and green, so they're easy to read if you're colour-blind.
• Your choice: in Settings, pick a theme, one of five boards (Travertine, Marble, Wood, Slate blue, Matrix) and a piece set (Classic, Ivory & bronze, Matrix red). The preview updates as you choose.

New: opening book manager

• Where: Local Engines is now Engines & Books, with a tab for your Polyglot opening books.
• At a glance: each book shows its size, how many positions it has and its favourite first moves.
• Manage them: add books with a button (or by dropping a .bin file), open the books folder, or delete a book you don't need.
• Explore a book: click any book to walk through it move by move on a board, with how often the book plays each move.

New: customise the sidebar

• Your order: click Customize at the bottom of the tab list and drag the tabs into the order you like.
• Hide tabs: hide the ones you don't use with the eye button; Reset brings the original layout back.

Smaller changes

• Installer name: the Windows installer is now built as Coliseum-Setup-<version>.exe, which matches the update file without renaming.

New: SPRT testing

Find out whether a new build of your engine is really stronger, the way Fishtest and OpenBench do it.

• New format: pick SPRT Test in the tournament lobby, choose the new engine and the base engine, and Coliseum plays game pairs (same opening, colours swapped) until the test decides.
• Your bounds: set Elo0, Elo1, alpha and beta, or use a preset: gain [0, 5], big gain [0, 10] or no regression [-5, 0]. A game limit stops tests that never decide.
• Live results: the log-likelihood ratio between its two bounds, the Elo difference with a 95% range, the likelihood of superiority, W/D/L and the game-pair counts (pentanomial).
• Clear verdict: "H1 accepted" means the new engine is stronger; "H0 accepted" means it isn't. Games still running when the test decides are stopped and not counted.

New: adjudication

Games that are already decided no longer have to be played out to mate.

• Resign: both engines agree one side is losing by at least a set score for a set number of moves.
• Draw: after a set move, both engines' scores stay close to 0 for a set number of moves.
• Move limit: a game that runs past a set length is a draw.
• Where: adjudication works in tournaments, SPRT tests and Elo estimation, and is marked as "adjudication" in the PGN.

New: search limits

Besides a clock, games can now use a fixed time per move, a fixed search depth or a fixed number of nodes. Fixed nodes make results independent of how busy your PC is.

New: opening suites from EPD and PGN files

• Any suite: use EPD position files or PGN files (like the 8-move or UHO suites), in tournaments, SPRT tests and Elo estimation.
• Pairs: each opening is played twice, once with each engine as White.
• Options: play them in file order or shuffled, and choose how many moves of each PGN line to play.
• Checked first: Coliseum counts the openings when you pick the file, so a broken file shows up before the start.

New: WinBoard engines

• Detected automatically: Coliseum now supports WinBoard (xboard / CECP) engines as well as UCI. It asks each engine which protocol it speaks, and you can also set the protocol by hand in the engine's settings.
• Options: WinBoard engines' own options show up in Configure, like UCI options do.
• What works: WinBoard engines play in tournaments, SPRT tests, Elo estimation, Quick Match and Play. Analysis, Game Review and the Tactics Trainer still need a UCI engine.

New: Linux version

• Downloads: Coliseum now runs on Linux too, as an AppImage or a .deb package. AggroChess and Stockfish 17.1 come with it.
• Your files: engines and books you add on Linux are kept in ~/.config/coliseum.
• Updates: the Linux version updates itself from GitHub, just like the Windows one.