1.Bd3 Sxg5 2.Kxg5 Sd4 3.Kh4 Sf3# (MM)

1.Rd3 Sxg3 2.Kxg3 Sd4 3.Kh4 Sf5# (MM)

Active sacrifice (white) × 2

Analogy (complete)

Chumakov theme (p-b, simplified, 2, 2)

Exchange of functions (bBb1/bRa3, Interfered / Interfering)

Exchange of functions (bBg3/bPg5, Captured / Passive self-block)

Exchange of functions (wSf3/wSf5, Active sacrifice / Mate)

Grimshaw (black)

Many-ways (bK, 2)

Play on the same square (B1, 2)

Play on the same square (W2, 2)

Zilahi (active, SS, 2)

Model mate × 2