Semi-open games

Borg Defense

1.e4 g5

The Borg Defense starts with 1.e4 g5 and is catalogued under ECO B00, in the semi-open games half of the book. The catalog indexes 5 lines inside it, grouped into 4 named variations, and the position after those moves has 1 playable continuation to walk from here.

Opening repertoire map

Root edges show how often each move is played around your Elo. Use the arrow on a position to reveal the next replies.

Current position
Borg Defense
Popularity by Elo
Share of Lichess blitz, rapid, and classical games that continued with each move.
8
7
6
5
4
3
2
1
a
b
c
d
e
f
g
h

Current setup

Move ideas

  1. 1.e4

    Claims the center with a pawn and opens lines for the queen and king’s bishop.

    Idea: Build quick development and make early castling possible.

  2. 1…g5

    Advances the g-pawn to gain kingside space and control new squares.

    Idea: Prepare a fianchetto or discourage the opponent’s expansion on that wing.

Book continuations

Waiting for Lichess game popularity.

1 move
d4Borg Defense3 named lines · Borg Defense: Borg Gambit · Borg Defense: Troon GambitAdvances to d4 to claim central space and control nearby key squares.Idea: Give the pieces room to develop behind a durable central foothold.

Named variations

Each line below is an indexed entry under Borg Defense. Open one to load it on the board and keep exploring from that position.

Openings from the same volume

ECO groups openings by the structures they lead to, so these families tend to share plans with the Borg Defense.