Daily chess puzzle: Check Mate #371
Another puzzle from Dragoslav Andric’s 1981 book “Matni Udar”.
Black to play and mate White
Grobovski v Stefanovic, correspondence 1973
Solution
The main idea is obvious, but making it work needs a (slight) bit of thinking.
1…Nc4! forces 2 Bb8 when 2…Qg5+! forces mate: 3 Bf4 (or 3 Qf4) 3…Rb1+! drags the King to b1, when 4….Qb5+ and 5…Qb2 mates.
Update: from one of my readers
One of my readers (see comment below) has pointed out 2Rd8+ is a better defence, and indeed it is. As James says, it avoids mate, but after 2…Rd8 3Qg4 Na3! 4 Bd6[] Rb1+ 5 Kd2 Rd6+ 6 Ke2 Rh1 we reach the position below.
White doesn’t have a perpetual, and also can’t fork or trap the Na3, so Black will regroup and win.
FEN
1r4k1/4pp2/p2n2pp/1r5P/5Bq1/2P2Q2/P1P3P1/2KR3R b – – 0 1
allanbeardsworth 
The white reply 2.Bxb8 in your solution is NOT the best move for white. As tiubsay, it leads to mate. However, Rd8+! trades a rook for a queen and avoids mate! Black still has a major advantage, but a forced mate is prevented… at least for the time being.
Thank you, James. I have updated my posting to reflect your comment.