About this opening
English Opening: King's English Variation, Closed System is an opening in the Encyclopedia of Chess Openings,
classified under code A25. ECO group A (A00–A99)
covers flank and irregular openings, including the English, Bird, Réti and Dutch defences. This particular variation is reached
after 9 half-moves from the
starting position, with the move sequence 1. c4 e5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. d3.
It belongs to the English Opening family.
Within that family this is a level-2 branch (the King's English Variation → Closed System line). The immediate parent line is English Opening: King's English Variation, transitioned via 5.d3.
The opening sequence in prose form: 1.c4 e5, 2.Nc3 Nc6, 3.g3 g6, 4.Bg2 Bg7, 5.d3. From this position exactly one named continuation is recorded in the encyclopaedia.
Use the interactive board above to walk through the moves position-by-position. Click any move in the navigation to step backwards, or use the keyboard arrow keys. The list of recorded continuations sits directly below the board. For statistical data — how often master-level players have reached this position, White's win-rate, draw frequency, Black's score — see the panel in the right column.
Caissly's coverage of A25 extends through every named sub-variation in this line and across all four locales (English, Spanish, Portuguese, Russian). Where editorial commentary exists for a specific variation it appears as the page body; otherwise the page presents the structural data, board, and statistics as shown here.