About this opening
Modern Defense: Bishop Attack, Monkey's Bum is an opening in the Encyclopedia of Chess Openings,
classified under code B06. ECO group B (B00–B99)
covers semi-open games (1.e4 with Black playing anything other than 1…e5), with the Sicilian, French, Caro-Kann and Pirc/Modern at its heart. This particular variation is reached
after 8 half-moves from the
starting position, with the move sequence 1. e4 g6 2. Bc4 Bg7 3. Qf3 e6 4. d4 Bxd4.
It belongs to the Modern Defense family.
Within that family this is a level-2 branch (the Bishop Attack → Monkey's Bum line). The immediate parent line is Modern Defense: Bishop Attack, transitioned via 4…Bxd4.
The opening sequence in prose form: 1.e4 g6, 2.Bc4 Bg7, 3.Qf3 e6, 4.d4 Bxd4. From this position the encyclopaedia records no further canonical continuations — practical play branches into unnamed transpositions or returns to the parent line for alternative ideas.
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. 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 B06 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.