Puzzle of the Week #019

So last week’s offering was a bit of a thronker-of-an-endgame study, with White in a seemingly precarious position. Black was threatening promotion, and despite being a Rook to the good, White appears to have very few options – how to force the draw.

Cometh the hour, cometh the man… and our local Twitter celeb and top player, Jim stepped up with the winning moves. Congratulations Jim!

On to this week’s puzzle…

Black, an all-time great, has just played Bg5? How was that brutally punished? Answers in the comments please.