Colle, London, and Blackmar-Diemer Systems
T. D. Harding2 (knight)f3, 3 (Bishop)lf4 (sometimes called the London System). I also discuss some
variations (such as 1 d4 d5 2 (Knight)f3 c5 and 1 d4 d5 2 (Knight)f3 (Bishop)f5) which players
adopting these openings need to know. One advantage of these debuts is
their universality • White can play them against either 1 ... (Knight)f6 or 1 ... d5
and adapt them to more or less any subsequent development used by
Black.
The Colle and London Systems are more dangerous than their
reputations. They may be somewhat old-fashioned, but that too can be a
practical advantage. Players tend to study the variations used by
contemporary grandmasters to the neglect of the old. This does not,
however, invalidate the knowledge gained by the players of the past and
readers will therefore find many pre-war games (and even some pre 1914
games) in this book.