Welcome to Scratch Chess - Game of Kings! To start playing, simply click the white piece you want to move, then click the target field.
Next version preview: https://scratch.mit.edu/projects/161323175/
For bug reports please attach exported board data (the one before the black move took place). Simply click "Export", then look for the next-to-last board list entry and copy it to the clipboard (or export all entries to a file and copy the one entry from there). Alternatively you can also export he move list (click "Moves").
I focused on game experience and AI. Considering the speed limitations of Scratch it shouldn't be too bad (it calculates up to four moves in advance, depending on selected level).
- Mobility evaluation should be weighted per piece type and game stage
- Only wins accidentally (if at all) at level "Easy"
- Missing feature: PGN import / export (currently only customer format)
- Missing feature: FEN import / export (currently only customer format)
- Pawn jumps to wrong field in dutch opening
- Opening book is rudimentary (fixed by Grijfland)
- Evaluation functionality needs cleanup (currently cluttered code, with implicit dependencies)
- Bug: Disappearing piece due to wrong en-passant application during checkmate check (thanks to Itharius for reporting this)
- Bug: Wrong algebraic notation on H column (thanks to Itharius for reporting this)
- Bug: King passive in endgame due to latest performance tuning
- Feature: Performance tuning by evaluating position less frequently
- Bug: Allows castling through checked fields
- Feature: En-passant support
- Feature: Move ordering via hash move (speedup)
- Feature: Isolated pawn evaluation
- Feature: Algebraic move list
- Feature: Undo move
- Feature: Import/export board data
- Bug: Queen moves too early
- Bug: Cannot move h2h4
- Feature: Opening book initial implementation
- Feature: Provide several difficulty levels
- Bug: Does not detect draws on repetitive positions
- Bug: Black move might lead to black king being checked
- Bug: Missing double pawn evaluation
- Bug: Thinks one side's check can be compensated by other side's check
- Bug: Does not consider check on castling
- Bug: Does not consider draw in move evaluation
- Bug: Applies pawn promotion too late
- Bug: Target piece not restored after invalid white move when checked
If you like the game, please click ★ and ♥. Your feedback is welcome in the comments section.
Opening book by Grijfland
Intro screen picture:
Chess programming resources:
Tutorial (in German):