The aim of the player being a quick development of his forces, it is
advisable to bring each piece into play by attacking an adverse piece or
Pawn immediately, if possible. The Kt here attacks Black's K P.
... 2. Kt to Q B 3
This move not only defends the attacked Pawn, but at the same time brings a
piece into play, and thus establishes an equilibrium in the development. 2.
... Q or K 2, or 2. ... Q to B 3, would be unfavourable defences, because
the former move would prevent the development of the K B, and the latter
the _sortie_ of the Knight, besides exposing {355} the Queen to attack. It
may be taken as a general rule that it should be avoided as much as
possible to defend pieces of less value with pieces of greater value. Black
could also play here 2. ... P to Q 3, which is called Philidor's Defence,
or reply, by 2. ... Kt to K B 3, with an attack upon White's K P, which is
called Petroff's Defence. These will be treated later on.