very nice perpetual. Thanks for the study.

I guess Nd1 to get the black b-pawn is to easy? Although i can't find a way for black to win the white knight and have a knight at b8 to block the b- pawn at the same time.

I suppose we should look what happens after 1. Nd1 b1N...

I think Nd1 loose:

1. Nd1 b1N 2. b7 Nc5 3. b8 N Kb3 might loose.

1.Ne4 is another try.

1...Nc5 is annoying though.

I haven't found a good reply yet.

1. Nd1 - b1N 2. b7 Nc5 3. b8N Kb3 4. Ke7 Kc2 (night trapped?)

5. Nd7 - N somewhere 6. Nf6 and white's night escape.

Black can play 5. ... Ne4 to prevent 6. Nf6

But there might be somewhere a forced night exchange.

Black plays 5. ... Ne4 to prevent 6. Nf6

But there might be somewhere a forced night exchange.

Hm.. 5... Ne4 White still can play 6.Nf6:

6. Nexf6 7. Ne3 check and draw
6. Ngxf6 7. Nf2

5.Nd7 Nxd7+ is just two knights down

Sorry, I missed a move.

I think 2.Nb2+ is interesting
2...Ka5 (2...Ka3 3.Nc4+ Ka2 4.b7 Nc5 5.b8N; 2...Kb4 3.b7)
3.b7 Nc5
4.b8N Kb6 trapping the knight.

But 3.Nc4+ Ka6 4.Ke7 looks difficult to win for black. Black can't capture the pawn or drive the knight away.

5. Nd7 Nxd7 6. Kxd7 draw