chess online

In this puzzle you have a black rook that will literally defend all your moves and prevent mate in two. But if you look at the board carefully you realize that if it was Black's turn to move instead of yours, you will realize that the black king doesn't have any flight squares and the bishop can't move otherwise its mate. but the rook has plenty of moves it can make to ward off mate in two. as a matter of fact the rook can move any where except rook takes a5 cause the white knight takes and mates. This should make you realize that the rook can effectively leave the a5 to h5 file because the same white knight can't mate on e5 like it could when the rook took on a5 and the white knight took and mates. this is because if the white knight checks on e5 it will block the dark square bishop covering the d6 square. at this point you realize that not every thing is setup yet you simply move the bishop somewhere where it doesn't impede anybody else and can't be blocked either by the rook or the white knight from covering d6 or captured by the black king. Therefore bishop to b8 is the final touch to setup mate because now black would be in zugzwang!!

it's hard because of the amount of attempts vs solved. the more people fail to solve a puzzle the harder it is rated.