Meridian Chess Club

♞Meridian chess club

Board 1Engine · Expert00:00

Meridian EngineBlack · Expert

searching

00:00

0.00

YouWhite · human

00:00

Engine You play

Reading the sheet

Every move is written in Standard Algebraic Notation — the same language used on paper at the board. The score sheet is also your time machine: tap any move to rewind the game to that moment.

Nf3: Piece letter, then destination. Knights, bishops, rooks, queens, kings.
exd5: Pawn captures: the departing file, then x, then destination.
Nbd2: Disambiguation — which of the two knights on b and f moved.
O-O / O-O-O: Castles kingside / queenside. Both rook and king move.
e8=Q+: Pawn promotes to a queen, and it is check.
gxf1=N#: En passant capture underpromoting to a knight that mates.

Under the hood

Negamax with alpha-beta pruning, iterative deepening with a hard time budget, a transposition table, principal-variation search, late-move reductions, check extensions, null-move pruning, killer and history move ordering, and a quiescence search that only explores captures and promotions so the evaluation is never taken mid-exchange. Material, piece-square tables, pawn structure, passed and isolated pawns, bishop pair and rook files feed the evaluation.

Rules in force

Full legal move generation, including pins and checks
Castling — rights, empty squares, no castling through check
En passant, on the one chance you get
Promotion to any piece, chosen by you
Checkmate, stalemate, and check warnings
Threefold repetition, fifty-move rule, dead positions
Undo, board flip, hints, captured material tally

Keys & touch

N new game
U undo
F flip
H hint
Esc deselect
tap a piece, tap a square — or drag

Table etiquette

The clock in the corner runs for whichever side is to move, exactly like a real board. The bar beside the board is the engine's last verdict: bone colour climbing means it likes White.