13...Bxf5!Jann found the move! the second knight black needs for a nnqp mate while also taking out a defender of h4, not to mention the mate threat of Nf3 followed by Qh7, Qg7 or Qg8#13...Rxd8??14.Nf6+Kf815.Q@g8#14Nf6+...14.Qh4N@f3+15.Kh1Nxh414...gxf615Qxf6N@h3+16gxh3N@e2+17Kh1Q@g2+18Kxg2N@f4+19Kh1Bxe4+20dxe4@g2#IM opperwezen - LM JannLee, 0-1, -, lichess.org/a8ozlW2B
13...Bxf5!13...Rxd8??
05 Practice Opper to Move! (without variations): Jann to play 20161