Yavalath: An abstract board game for 2 or 3 players invented by computer program LUDI.

• Commercially available from nestorgames with sister game Pentalath.
• Ranked in top #100 abstract board games on BoardGameGeek in 2011 and won GECCO "Humies" gold medal in 2012.
• Article in November 2013 issue of Bitcoin magazine.
• Rules: Start with empty board. Players take turns adding pieces. Win by making a line-of-4, lose by making a line-of-3 beforehand, draw if board fills up. No passing.
• Tactics and Strategy: Key is forcing move. Unblocked lines of size 4 have good attacking potential, and size 3 lines are vulnerable. Prevent opponent from forming unblocked size 4 triangles. Games are short and decisive.
• Annotated Sample Game: Between highest-ranked players in 2008. Computer player's opening move was strong. Sequences of forced moves led to Black's defeat.
• Computer Player: Use UCT algorithm. Can make good plays without knowing game details.

• Variants:

  • Three-player version: Play by same rules with additional conditions. Winner is last surviving player or first to form a line-of-4.
  • Five-not-four: End conditions extended to winning on a line-of-five and losing on a line-of-four, played on larger boards.
• History: Rules by Cameron Browne and Cyberite Ltd in 2007. Designed by machine with name randomly created. Can be played on Richard's PBeM server. Many thanks to server regulars for testing.