The pgn4web chess engine analysis board is the latest module added to the pgn4web project.
When enabled, the chess engine analysis module allows for a popup analysis board to be invoked by the user with the E8 shortcut square (assuming White on bottom, D1 otherwise). The analysis board captures the current position and activates the chess engine, presenting both the calculated principal variation and the resulting position evaluation (hover the mouse on the evaluation symbol to read the numeric evaluation in pawn units). The engine stops analyzing after a set amount of time. At any point the user can try moves and explore variations by clicking the from and to squares for the intended move.
The analysis module uses the GarboChess chess engine. The performance of the javascript based engine is relatively limited compared to professional engines optimized for each processing environment; use the pgn4web analysis board for quick high-level assessments, for detailed analysis please refer to a chess engine optimized for the chosen computing platform. However, as you can see from this engine analysis example, the pgn4web engine analysis is able to spot immediately the winning opportunity for Kasparov with Qxd7 that decided the 11th game of the 1985 world championship against Karpov.
The chess engine of the analysis module requires a recent browser with support for the web worker functionality; if the chess engine is not available the user can still try moves and explore variations on the analysis board.
The chess engine analysis module is an optional component and it is not enabled by default on pgn4web chessboards; currently some of the pgn4web live pages have been enhanced with the pgn4web engine analysis module: try the E8 shortcut square at the pgn4web live fullscreen view, the pgn4web live mosaic view and the pgn4web live results view!
