Thematic tries:
1. Nd4 ? threat : 2. Kd7 and 3. Ne6 #
1....Be5 ! (1....Bg1 ? 2. Nf3 ! and mate in 2) 2.Nf3 Bf4 z 3. Kd7 Be3 !! z and no mate in 2.
1. Ne1 ? threat : 2. Nd3 Bd6 z 3. Kd7 (3. Kxd6 ? stalemate) and mate in 2 with 5. Ne6 #
1....Be5 ! 2. Nd3 Bd4 z 3. Kd7 Be3 !! z and no mate in 2.
1. Nb4 ! threat : 2. Na6 ! Bd6 z 3. Kd7 and mate in 2 with 5. Ne6 #
A) 1....Bb8 !
2. Nd3 !!
2. Na6 ? Ba7 ! z 3. Kd7 Bb6 !! z 4. ?
2....Bd6 z (firstly decoved to b8, B cannot go to d4 and therefore loses the focus. See thematic try 1. Ne1 ?).
3. Kd7 !
3....B~
4. Nc5 or Nf4 and 5. Ne6 #
B) 1....Bg1 !
2. Nc6 !!
2. Nd3 ? Bd4 ! z 3. Kd7 Be3 !! z 4. ?
2....Bh2
3. Kd7 !
3. Nd4 ? Be5 ! 4. ?
3....Bc7(e5,g1) (decoved to h2, B cannot go to b6 and therefore loses the focus.)
4. Nd4(d8) and 5. Ne6 #
Focal play in miniature form with a decov of Bishop in order to prevent a new focal opposition after
a change of the initial mating square (A line) (Author)