a)

1.Rd2*d4 ! threat: 2.Rd4-d5 #

1...e4-e3

2.Qc1*e3 #

1...c5*d4

2.Qc1*g5 #

1...Ke5*d4

2.Qc1-c3 #

b) bPc5-->b6

1.Qc1-c3 ! threat: 2.Qc3*d4 #

1...d4*c3

2.Rd2-d5 #

1...h4*g3

2.Qc3*g3 #

Zilahi

Capture d'une pi čce clouante par la pičce clouée

Kniest

Cle de sacrifice

Captures reciproques

Clouage direct

Cle ampliative