The K could not well move to f1, for the O would have checked at e3, and then taken the L.

19,L g5
20,N b2

The N might have moved to f4, but then the black L would have taken the P g2, and won. Indeed, White’s game is hopeless, as the following diagram and the solution show:—

12 + 11 = 23 pieces.

Black to play and mate in eight (8) moves.

Solution.
20,M f2:†
21,K f2:

If K d3, the mate follows in three more moves by L e3:, O b6, and P c5.

21,L e3:†
22,K f1M f8†
23,N f5M f5:†
24,L f3M f3:†
25,P f3:L f3:†
26,K g1N c5†
27,N d4N d4:‡