Changelog

Updates, additions and improvements to Polygammon

Version 0.56.0 Latest

1 Apr, 2026

Development

  • Major Change: The application has been renamed from Palamedes to Polygammon.
  • Updated Qt to 6.11.0
  • Updated Eigen to 5.0.1
  • Default installation folder moved to "Program Files\Polygammon"

Core

  • Portes/Backgammon: optimizing 2 expert inputs resulted in 3-4X speedup.
  • Plakoto-Fevga/Narde: small speedups (up to 50%) due to optimizations in move generation.
  • Fevga: fixed bugs in move generation in rare situations when the no-blocking move is in effect.
  • NN Evaluator: a few optimizations resulting in faster evaluations.
  • Cache: major redesign, now it has multiple caches for each ply. All memory reserved at startup.
  • Algorithms: added new search algorithm NegaBatch^2.
  • Evaluators: adden new evaluator: 1-sided bearoff DB. Not exact but very accurate.
  • Many other smaller fixes and performance improvements.

UI

  • New UI look and feel based on Win11 theme. Supports dark mode, accessibility options when set in Win11 settings.
  • New French translation. No need for program restart when changing language.
  • Better logging with new search.log file that shows search settings, and option to log debug info.
  • Fixed crash with small pinDBs.
  • New View Menu option that shows/hides toolbar, scoresheet, pips, board numbers, and status bar.
  • Toolbar can now be moved to other edges of the program window.
  • Opening tavli files directly from windows are now loaded correctly.
  • Start Game: tavli matches can start from 3.
  • Many other smaller fixes and improvements.

Version 0.55.0

1 SEP, 2025

Development

  • Updated Qt to 6.9.2

Core

  • Algorithms: Added multithreading to NegaBatch and IDDFS search algorithms
  • Algorithms: Removed stats.currentMove and added movesCompleted. This statistic is better suited for multi-threaded search

GUI

  • Start position can now be saved/loaded to/from .tavli files
  • Fixed visual glitches when AI has finished thinking before computer dice has finished animated
  • Added pips inside board
  • NeoAnalysis: User can expand multiple moves at once (with right click)
  • NeoAnalysis: Fix boldness of Diff column
  • NeoAnalysis: Board move is now added inside search and not expanded after analysis has finished
  • Advanced: Removed old analysis window

Version 0.54.1

1 AUG, 2025

Development

  • Updated Qt to 6.9.1
  • Palamedes now needs AVX2 support from CPUs (released after 2013 except Pentiums and Celerons)

Core

  • Evaluators: NNs can now handle state size above 2000

GUI

  • NeoAnalysis: Added progressbar and stop button. Search is now run on a different thread and can be stopped
  • NeoAnalysis: Fix crash when id is plakoto
  • NeoAnalysis: Fix match score inside id when opening from board
  • Start game: Starting from XGID now gets the score of the match from the ID
  • Benchmark: Added stop button to stop the process
  • Options: Added number of decimals for analysis values
  • About → Help: Manual file now opens correctly
  • PlakotoDBs: When "big" version is not found try to load "small" version. Also moved files to new PlakotoDBs folder

Version 0.54.0

26 MAY, 2025

Development

  • Updated Qt to 6.8.3
  • Palamedes now needs FMA support from CPUs (released after 2013 except Pentiums and Celerons)

Core

  • Algorithms: Added pruning nets to Analysis and Play
  • Algorithms: Added cache to Analysis and Play
  • Combined prune + cache give the following improvements on average:
    • Portes: 3ply: 2X, 4ply: 2X, 5ply: 3X
    • Plakoto: 3ply: 1.7X, 4ply: 1.8X, 5ply: 2.5X
    • Fevga: 3ply: 1.6X, 4ply: 1.8X, 5ply: 3X
  • Algorithms: "Huge" filter now up to 32 moves (from 20)
  • XGID: added error checking for illformed IDs

GUI

  • Start game dialog: Doubling cube text on the left
  • NeoAnalysis: new way of showing stats, added more stats
  • NeoAnalysis: detect correctly "All rolls (00)" in XGID
  • NeoAnalysis: fixed bug: filters where not copied from settings
  • New options for dice colors and shadows. Shadows can be disabled and the color of dice can be changed to be the same as the player's checker.
  • Match play: fixed the start game player bug on the second game of a match when the player plays first.
  • Added palamedes folder in help, added icons in other items in the help menu.

Version 0.53.3

24 MAR, 2025

Core

  • Algorithms: added search for all rolls
  • Algorithms: added some optimizations for search, new map for NegaTTExpectimax (30% less memory, 15% faster)
  • Evaluators: added pubeval evaluator for portes/backgammon games

GUI

  • Fixed major bug in match play: match options were not applied
  • NeoAnalysis: all rolls of a position can now be analyzed and shown in a single table. Rolls are sorted by value and the weighted average is also calculated.
  • NeoAnalysis: removed bold column
  • NeoAnalysis: selected move can not be expanded if terminal
  • NeoAnalysis: the played move is now analyzed at the max-ply depth
  • Options: fixed dice tab

Version 0.53.2

24 FEB, 2025

Development

  • Updated Qt to 6.8.2

GUI

  • New game: Switched to new search algorithms (IDDFS). Games can be played up to 4ply
  • NeoAnalysis: Alternate row color in table is now a lighter gray
  • NeoAnalysis: Added column "Diff" which shows the value differences from the best move. Thresholds and colors can be adjusted in options
  • NeoAnalysis: Added One-Sided PinDB Evaluator when applicable in plakoto positions
  • Start new game: Non-advanced users can play up to 4ply
  • Options: Added new filters, removed old AI search options
  • Options: AI resign thresholds now configurable
  • Board: Better positioning of the checker(s) on the bar (closer to board's center)

Version 0.53.1

29 JAN, 2025

Development

  • Updated Qt to 6.8.1
  • "Engines" category is now split in several subcategories starting with Core: Core, Core:Evaluators, Core:Algorithms

Core

  • Backgammon: Fixed score (3, -3) when losing player was on bar
  • Takhteh: Rule "No hit and run" fixed to "No hit and run for cover"

GUI

  • New form for analyzing positions with features: Analysis up to 5ply, Configurable match options, Configurable search algorithm, Dice roll can be changed, Moves can be selectively analyzed to deeper plies with a right-click
  • New game: Fixed bug when selecting 2nd best NNs in a Tavli match
  • New game: Default chance filter is now OneMove (1)

General

  • Added translations in some standardButtons

Older Versions

2013 - 2024

Click on individual versions below to see their release notes.

Version 0.52.3 2 OCT, 2024

Development

  • Updated Qt to 6.8.0 RC

Engines

  • Fixed crash when AI pondered cube actions in a backgammon game

GUI

  • Added new menu item "Analyze From ID" to Game Menu
  • Fixed result and message when player drops the cube
  • Fixed XGID visual issues in analyze window
  • Changed name of "Tapa" variant to "Start with 3 stacks"
  • Changed names of Tavli AIs in start game dialog

General

  • Fixed bug: Language change was not applied at next startup
  • Fixed bug: Error in .tavli file when saving game with manual dice and start player is CPU
Version 0.52.2 26 SEP, 2024

Engines

  • Added Narde NNs (Narde-1, Narde-2)
  • Fixed bug: wrong 3-ply evaluation when terminal moves exist

UI

  • Added Narde analysis
  • Added highlighted color to options
  • Analysis window visual improvements
Version 0.52.1 9 SEP, 2024

Engines

  • Added match play
  • Added Tavli variant
  • Added Backgammon variant
  • Added 3ply search

UI

  • Export positions to XGID format

Other

  • Updated Qt to version 6.8.0 beta 4
  • Many bug fixes and performance improvements
Version 0.47a 8 AUG, 2013

Engines

  • Neural Network implementation now uses the Eigen library and SSE2 intrinsics. Up to 3x faster Neural Network computations, up to 2x faster in actual play
  • Palamedes may not run on old processors that do not support the SSE2 instruction set. Processors newer than 2006 should be fine
  • Fixed bug in Narde's move generation: Incorrectly allowed primes in opponent's home board when the point right before the home board is occupied

UI

  • New option enables the computer opponent to resign a double game when it detects that there is 98% or more probability of losing a gammon (Default: Enabled)
  • Fixed bug: when in automatic playing mode and the user resigned a game while moves where played automatically, the game was not stopped
  • Files with .tavli extension are now associated by default with the Palamedes program
Version 0.46a 3 MAY, 2013

Engines

  • Added Hypergammon variant. Up to 6 starting checkers supported. Portes NNs are used for AI opponents
  • Added Nackgammon variant. Portes NNs are used for AI opponents
  • Added Takhteh variant. Portes NNs are used for AI opponents
  • Added several optional rules for Portes variant: Egyptian Rule, Nackgammon start position, No pip wastage in bearoff, No hit and run in player home board

UI

  • Program now displays filename and gametype of current game on the title bar
  • New Statistics dialog. Statistics are updated by gametype and AI opponent after the end of a game
Version 0.45a 14 FEB, 2013

Engines

  • Added Narde variant. AI opponent can be a Fevga neural network
  • Fixed bug in Fevga's move generation method when in a special case of the Fevga Start rule
  • Optimized Fevga's move generation method by 15%
  • Added rules for subvariations of Fevga, Plakoto
  • Added pin databases for the Plakoto variant

UI

  • Simplified start game dialog and options dialog
  • Added options for Plakoto, Fevga rules
  • Added 4 pseudo-random dice generation methods with seed support
  • Fixed crash when loading game files with errors
  • Loading a game file now displays the last position of the game
Version 0.44a 2 DEC, 2012

Engines

  • Added Plakoto-5, Fevga-6 engines. These engines are stronger than the previous ones
  • Removed some weak engines

UI

  • New option: change checker color
  • New option: automatically check for new version at startup
  • New option: faster play and automatically play forced moves
  • New option: select program language (English, Greek, German supported)
  • Pipcount can be viewed in the toolbar
  • Added program manual in English

Other

  • Program now installs using NSIS Nullsoft installer
  • Fixed program icon
Version 0.43a 22 AUG, 2012

Engines

  • Portes/Backgammon can now use a special 2-sided endgame database. This DB is loaded on startup if it exists

UI

  • Added option that prunes the move list keeping the x best 1-ply moves for expansion to 2-ply. When set to 0 all moves are expanded
  • User can now remove the remaining moves of a game starting from a selected position on the scoresheet