Fourth Release V1.12

V1.12 (ZIP), released 14-Oct-2017, is the fourth stable version.

Changes from V1.11

  • Besides overclocking, underclocking is available as well – down to 10 %.
  • Removed the “soft time per move” feature. Instead, the move time is given as average.
  • Fixed endings with opposite coloured bishops so that the kings’ positions do not outweigh an additional pawn loss.
  • Added draw detection for KQ:KP when the pawn is a rook or bishop pawn on the 7th/2nd rank with its king nearby and the other king sufficiently far away.
  • Added draw detection for KR:KP when the pawn is on the 7th/2nd rank with its king nearby and the other king sufficiently far away.
  • Added selective deepening for passed pawn pushes in the endgame.
  • Quiescence search detects checking captures and evasions.
  • Fixed a bug that prevented the detection of 50 moves draw in the search tree.
  • The draw avoidance during the opening checks more thoroughly whether or not to allow draw by repetition.
  • The hash tables are used also in the pre-search phase for move ordering.
  • The hash table clearing is done via age management.
  • During search, the PV is preserved if possible, preventing PV shrinkage because of hash table cuts.
  • Added more opening knowledge.

UCI versions

  • Changed the protocol from Winboard to the more popular UCI.
  • Added an Android and Raspberry Pi version (binaries supplied).
  • Added a CPU throttling feature, available through UCI.
  • Quick reply moves work correctly.

Known issues

    All versions

  • The added deepening features degrade the performance.
  • With the 50 moves rule, checkmate is not given precedence over draw in the 50th move.
  • In the rook vs. bishop endgame, the correct edge is not highlighted enough over its adjacent rim squares, which occasionally might lose a game.
  • Embedded target

  • Undoing or redoing moves within the opening book range deletes the little ‘b’ that denotes book moves.
  • UCI versions

  • The half move counter of the FEN string is interpreted in moves instead of half moves.
  • With fixed search depth, the final PV is printed twice.
  • The returned answer move is actually executed on the internal chess board. Some GUIs may run into problems when repeatedly using the UCI feature “searchmoves” for the same position if they do not send new “position” commands inbetween.
  • The engine idle state keeps the OS from entering deeper energy saving modes.