Kupper – Leepin
White to play
Black has nothing to fear from 27 Qd8+ Kh7 28 Nf8+ Kh6 29 Qd4 Re2 when the position is equal.
A brilliant move, and the only decisive one.
27…Qxe5 fails to 28 Nxg6 fxg6 29 Qc4+ wining the rook on a2.
Dr Josef Kupper (1932–) is a Swiss master who retired from active play in the 1960s to pursue a banking career. He won the Swiss Championship in 1954.
Here he dispatches a former world champion with another conclusive (but easier to find) knight-to-the-side move:
Euwe – Kupper
Mont Chaumont, 1958
Black to play
A curious position where the rooks and knight threaten to mate both kings.
Black strikes first:
It’s mate after 42 Kc1 Ra1+ 43 Kd2 Rb2+, because the knight covers the c3 escape square.