The
German word for "
air",
luft is used in
chess terminology as an abbreviation for
luftloch meaning "airhole". The airhole in question is an escape square constructed for the
castled
king by moving one of the
pawns in front of him forward, giving a configuration such as this:
+---+---+---+
| | P | |
+---+---+---+
| P | | P |
+---+---+---+
| | K | |
+---+---+---+
This is an effective way to guard against a
back rank mate, since in the event of a
rook or
queen invading the back rank, the king can simply step forward into this hole, thus evading
checkmate.