History of published releases:
Fischerle 0.9.80 SE (March 24th, 2017):
- a sightly more aggressive forward pruning scheme is now applied, employing smaller margins for futility pruning, extended futility pruning, and limited razoring;
- adding delta pruning and implementing some further slight enhancements, quiescence search has been mildly refined;
- the piece value assigned to bishops and the pair-of-bishops bonus have been slightly reduced, taking into account observations in practical play as well as the empirical findings by Larry Kaufman;
- king safety evaluation has been refined, adding an additional incentive to keep some safety-critical castling-side pawns in their initial position;
- Fischerle’s mate approaching scheme has been enhanced; moreover, a minor inconsistency has been eliminated that caused Fischerle to come up with an illegal move in some very rare cases in which the opponent, while mating Fischerle, deviated from the optimal line of play;
- Fischerle now exploits as well the results of partially completed iterative deepening cycles in case the search failed high at that level.
Fischerle 0.9.70 SE (March 25th, 2016):
- singular extensions (which, in the standard setting, don’t apply at Cut nodes; moreover only moves from the transposition table the value of which is marked there as exact or lower bound can become singularity candidates) implemented; [For an example of how singular extensions improve tactical strength, see here.]
- dedicated scoring functions for some further (typically drawn) pawnless endings added;
- scoring penalty for „drawish“ opposite-colored bishop endings implemented;
- search extension that applies when a pawn ending is reached added;
- some minor inaccuracies of the static evaluation function eliminated;
- multiple bishops of identical field color (which might result from underpromotion) are now adequately scored as a draw where applicable.
Fischerle 0.9.65 (September 14th, 2015):
- material evaluation enhanced (and simplified);
- some minor inaccuracies in the treatment of particular endgame types eliminated.
Fischerle_0_9_61 (February 4th, 2015):
- some minor transposition table inaccuracies eliminated;
- not to be subjected to formal testing and ranking (CCRL etc.), since the differences to its predecessor Fischerle_0_9_60 regarding both playing strength and style are very small.
Fischerle_0_9_60 (October 7th, 2014):
- Late Move Reduction (LMR) added.
Fischerle_0_9_50 (May 15th, 2014):
- the king plays a more active role in late middlegame / early endgame;
- most instances of some important types of draw (viz., particular positions of type king vs. rook pawn or king vs. rook pawn and wrong-colored bishop) are now properly recognized;
- configuration file config.ini enables the user to alter some supplementary settings (such as the font and font sizes to be employed for displaying chess pieces in Fischerle’s proprietary GUI).
Fischerle_0_9_30b (August 10th, 2013):
- this is the first officially published distribution;
- official 32 bit version, featuring properly adapted (i. e., slightly increased) numbers of hash table entries, has been added on April 23rd, 2014.