Underpromotion 2

Underpromotion 2

Jul 29, 2008, 7:38 AM |

I just want to cover two other situations where underpromotion is necessary to avoid stalemate, one where it is required to promote to a Bishop, and one with a Knight.

First, the Bishop.

In this position we should examine the natural promotion to a Queen.











Now black cannot promote
 his pawn, and the only move he can make is 3 ... Kh3, allowing the white king to take control of the key squares of the g-pawn, 4.Kf2

Also, if the white pawn was on h5 instead, only promotion to a Rook would win.







Promotion to a Knight.

Notice that a Rook here would also stalemate.







So, we must promote to a Knight!

Here a Bishop would be insufficient to stop that a-pawn from promoting.

After this series of moves Black must move his king away from the defense of the a-pawn, allowing white to make the move 9.Ka2






So promotion to a Queen isn't always the only way to handle yourself.