Deep Becky 0.2 - new version chess engine

Deep Becky - UCI chess engine
Author: Diogo de Oliveira Almeida

Deep Becky was born from a simple question: "Can AI create a functional UCI chess engine from scratch?"

Development began around July 2025 using conversations with ChatGPT to create the C++ code. The AI wrote 100% of the code while I provided guidance, testing, feedback, and strategic decisions about next steps.

The path was quite challenging - copying code from chat conversations to Notepad, attempting to compile, facing countless compilation errors, and when it finally compiled, dealing with recognition issues in Fritz. After many attempts and corrections, going through engines that weren't recognized, didn't make moves, or made illegal moves, I finally achieved functional code that respects all chess rules.

Deep Becky 0.2 what's new?

Version 0.2 implements Aspiration Windows in Iterative Deepening.

Improved Evaluation

Mobility

Version 0.2 adds a mobility term for rooks and queens, counting free squares on horizontal and vertical lines. Pieces with greater mobility receive bonuses.

Piece-Square Tables (PST)

Separate and optimized PST tables for each piece type, including distinct tables for the king in middlegame and endgame (PST_KING_MG and PST_KING_EG).

Bishop Pair Bonus

Detection and bonus (+25 centipawns) for the side that has the bishop pair.

Bug Fixes

Pawn Attack Verification

Critical fix in the isAttacked() function: the pawn attack direction was inverted in version 0.1, causing failures in pawn protection detection.

Board Restoration (undoMove)

Fix in board restoration after castling moves, preventing piece duplication or state corruption.

Deep Becky 0.2 download