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Chess openings

Opening family

Modern Defense Lines and Variations

The Modern Defense family contains 39 named lines in this opening book, spanning ECO A04 to B27. Use this page as the map, then open individual lines for exact move orders and diagrams.

Named lines
39
ECO coverage
A04, A40, A41, A42, B06, B07, B27
ECO volume
A (flank openings, irregular first moves, and many English/Reti structures); B (semi-open games, especially Sicilian, Caro-Kann, Pirc, Alekhine, and related systems)
Shortest line
B06 Modern Defense: 1. e4 g6

How to study this family

White

White should use the move order as a checkpoint: finish development, identify the central break, and compare the continuations below before memorizing moves.

Black

Black should ask what White is threatening in the center, then choose development moves that prepare a clean pawn break or a useful exchange.

Start with the shortest line, then branch to the variations that change the pawn structure or tactical target. Memorizing every branch before understanding the family plan is usually wasted work.

Main named lines

Deep theory branches

Start with the root lineDrill this family