37. Kh3 Qg5 threatening mayhem on g4. Best is 38. Qg1 to protect g4; then ...Re7 gets rid of the knight, one way or another, and g4 goes bang anyway. 37. Kg3 Q

37. Kh3 Qg5 threatening mayhem on g4. Best is 38. Qg1 to protect g4; then ...Re7 gets rid of the knight, one way or another, and g4 goes bang anyway. 37. Kg3 Qd6+; Kh3 or Kh4 Qh6 threatening mayhem on the h-file. 37. f6 Rf7 followed by hxg4 and g3+ and the WK has nowhere to hide. If, say, 38. Qf1 hxg4; Kg3 to stop this then Qd6+; Kh4 g3+ and White is toast. In some variations B can just play ...Rxf6 instead of ...hxg4, and again the WK ends up with nowhere to hide. (I'm a patzer, or more precisely a rusty club-level player; the above is the result of some experimenting with a strong computer program. I may have missed important things.)