Explanation

Protecting a square is insufficient, if the protector can be captured.

The following diagram illustrates the most common ways to remove a defender of a skewer:

The black knight on h5 defends f4, preventing White from winning the b8 rook with the skewer Bf4+. This defense has holes, and White can win by removing the defender in a few different ways:

• White can capture the defender with 1.Rxh5! Now either 1...gxh5 loses a rook to 2.Rxf6+, or else Black trades rooks first with 1...Rxf1+ 2.Kxf1 gxh5, still leaving f4 undefended and letting White win with the skewer 3.Bf4+.
• White can attack the defender with 1.g4! Again, after 1...Rxf1 2.Kxf1 Nf6 (or Ng7) the square f4 is no longer defended and White can play the skewer 3.Bf4+.
• In addition to defending f4, the black knight is also protecting the rook on f6. The knight is overloaded. White can deflect the defender with 1.Rxf6+! After Black recaptures with 1...Nxf6, the knight no longer defends f4 and White wins with the skewer 2.Bf4+.

Examples

White can temporarily sacrifice the exchange to capture the defender of the skewer: 1.Rxc6+! bxc6 2.Bd8+ Ke5 3.Bxh4.

Be4 would be a skewer, but e4 is guarded by the black knight on f6. White can win by capturing the defender: 1.Bxf6 Bxf6 2.Be4 Qxe4 3.Nxe4 Bxe4.

White can win with 1.Nxd5, capturing the defender of b4 and clearing the way for the bishop 1...exd5 2.Bb4 Qf7 3.Bxf8 and White has won the exchange.

Related combinations

There are various ways to remove the defence. In addition to capturing the defender, other ways to remove the defence include deflection, and attacking the defender.