Batteries
A battery is two of your own same-colored sliding pieces -- rooks, bishops, and queens -- lined up behind each other on the same file, rank, or diagonal, both able to see straight down that line. A rook backed up by a queen on a file, or a bishop backed up by a queen on a diagonal, are both batteries. The strongest version, two rooks plus a queen all stacked on one file, is nicknamed 'Alekhine's gun.'
The point of a battery is that it doubles the pressure a single line can put on a target square, file, or piece. If the front piece eventually captures or gets captured, the piece behind it is still aiming down the exact same line and immediately takes over the attack -- the opponent can't simply deal with the front piece and call it handled.
Batteries are especially useful for breaking through a well-defended square or piece: a lone rook attacking a defended pawn might be an even trade, but a rook-plus-queen battery attacking the same pawn means the defender needs two defenders, not one, or the point falls.
Because a battery only requires a clear line between the two pieces (not a target at the end of it yet), it's something worth building in advance -- lining pieces up on a file or diagonal before there's anything concrete to attack, so the pressure is already in place the moment a target appears.
Worked examples
Queen and rook battery on the d-file
White's rook on d3 and queen on d1 are stacked on the d-file, both aiming the same direction with a clear line between them.
Doubled rooks battery on the d-file
Black's rooks on d7 and d5 are stacked on the same file with nothing between them -- a battery.
Bishop battery on a diagonal
White's bishops on c2 and e4 sit on the same diagonal with the d3 square empty between them -- a battery along the diagonal rather than a file.
Test yourself
Click both pieces that form the battery on the d-file.
0 of 2 found