1001 Chess Exercises for Beginners The Tactics Workbook that Explains the Basic Concepts, Too

White to move
Solutions on page 129
Double check is a type of discovered
check where one piece moves to give
check and uncovers another piece
that also attacks the king. Needless
to say this is a bombshell and two out
of the three possible ways of
defending the king no longer apply: it
is not possible to interpose with a
piece, as check arrives from two
directions; you cannot capture the
checking piece because there are two
of them. The only remaining hope is
to move the king to a safe square,
presuming there is one ...
controlled by the two attacking
pieces. It is amusing to note that both
the checking pieces are hanging, but
because of the power of a double
check they are immune from capture.
The following diagram shows the
superiority of a double check compared
to a normal discovered check.
In the above position White ends
the game with the killing 1. c6#.
The king's two escape squares are
Black, with an enormous material
advantage, hopes to finish things off
immediately with 1... li:Jc4+ ?. This
would be a grave error, as White can
reply with a double check: 2. li:JcS+
'it>c8 (Black cannot capture either the
queen on b2 or the knight on cS due
to the double check) 3. 'W'h8#
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