[ Battery of
English cannon[1]
A Battery in chess is a formation of two or more
sliding pieces with common
attacking directions along the same
rank,
file, or
diagonal. Their attacks conjoin on one or more
target squares in one
ray-direction, attacked at least once directly, and one or more times indirectly. A battery is a chess tactics related term, often motivated by
strategicpawn structure related considerations. In the
middlegame, a (
rook) battery attacking a
weak opponent pawn on a
half-open file is a common motive. The German chess term Drucksäule[2] (tower of strength) refers to own, apparently weak pawn support from its
rearspan, to force a
lever and pawn exchange to (half-) open a file.
Like other
X-ray related tactics, considering batteries may be subject of
king safety terms and
static exchange evaluation. A standard pattern in
mate at a glance is a battery of
bishop /
queen or
rooks / queen, where the queen attacks a square or opponent piece adjacent to the opponent
king, exclusively defended.
With two bishops traveling on opposite colored squares there is no possibility of any duplication of function. So, in theory, rather than giving a bonus to two bishops, we should penalize every other combination of pieces, but it is obviously much easier to reward the bishop pair.