[Event "New to nuke: Rook invasions: Exercise: making luft"] [Site "https://lichess.org/study/2lC2jkJj/WKgOe2ld"] [Result "*"] [Variant "Atomic"] [ECO "?"] [Opening "?"] [Annotator "https://lichess.org/@/Illion"] [FEN "3r3k/8/8/8/8/4PP2/1PP4P/5K2 w - - 0 1"] [SetUp "1"] [UTCDate "2017.09.14"] [UTCTime "16:21:00"] [Source "https://lichess.org/study/2lC2jkJj/WKgOe2ld"] [Orientation "white"] [ChapterMode "gamebook"] { White to play. Black is threatening a rook invasion, and the white king currently doesn't have much space. What move allows white to avoid mate? } 1. h4! { This creates a safe 2x2 square (g2, h2, g1, h1), so if 1...Rd1+, 2. Kg2! draws. } { [%csl Gg2,Gg1,Gh1,Gh2] } (1. h3? { This doesn't create enough space, and black wins with 1...Rd1+ 2. Kg2 Rg1+ 3. Kf2 Rf1+ and 4...Rxf3#. } { [%csl Gg2,Gg1,Gh1,Ge1,Gd1,Gf1] } 1... Rd1+ 2. Kg2 Rg1+ 3. Kf2 Rf1+) (1. f4? { This doesn't create a 2x2 square, and black wins with 1...Rd1+ 2. Kg2 Rg1+ 3. Kf2 (3. Kh3 Rg4! then ...Rh4+ and ...Rxh2#) Rf1+ with an explosion or winning pattern next. } { [%csl Gf2,Ge1,Gd1,Gg1,Gf1] } 1... Rd1+ 2. Kg2 Rg1+ 3. Kf2 (3. Kh3 Rg4 4. f5 Rh4+) 3... Rf1+ 4. Ke2 (4. Kg2 Rf2+) (4. Kg3 Rxf4#) 4... Re1+) (1. e4? { This doesn't create a 2x2 square, and black wins with 1...Rd1+ 2. Ke2 (2. Kg2 Rg1+ 3. Kh3 Rg4 with ...Rh4+ and ...Rxh2# next) Re1+ 3. Kd3 Rxe4#. } { [%csl Ge2,Gd1,Ge1,Gf1,Gg1] } 1... Rd1+ 2. Ke2 Re1+ 3. Kf2 (3. Kd3 Rxe4#) (3. Kd2 Re2+) 3... Rf1+) 1... Rg8 { Black tries to cut the white king off from the newly-created square. What now? } 2. f4! $10 { Expanding the safe zone. The king is now already within the safe area, and black has nothing better than perpetual check. You have solved the exercise! Click on "Analyse" to see what the other white moves led to. } { [%csl Gf2,Gf1,Gg1,Gg2,Gh2,Gh1] } (2. e4? { White's king is cut off from the safe square in the corner, and 2. e4 doesn't give an alternative. Black wins here with 2...Rg1+ 3. Ke2 Re1+ 4. Kd3 Rxe4# (or 4. Kd2 Re2+ and 5...Rxc2#) } { [%csl Ge2,Ge1,Gd1,Gf1,Gd3] } 2... Rg1+ 3. Ke2 Re1+ 4. Kd3 (4. Kd2 Re2+) 4... Rxe4#) (2. Ke1? { An interesting try to escape up the board via d2 and c3, but it fails here because of the b2-pawn; 2...Rg1+ 3. Kd2 Rd1+ 4. Kc3 Rd4! and either ...Rc4+ or ...Rb4+ is coming next with a winning pattern. } 2... Rg1+ 3. Kd2 Rd1+ 4. Kc3 Rd4 5. Kb3 Rb4+) *