[Event "?"]  [Site "?"]  [Date "2017.06.06"]  [Round "?"]  [White "Tactics #55"]  [Black "   Sutovsky - Giri, Zürich, 2009   "]  [Result "*"]  [SetUp "1"]  [FEN "r1b1k2r/4bpp1/8/3pP3/p5Pp/Pp1qB2P/1P2NQ2/K1R4R b kq - 0 1"]  [PlyCount "15"]   1... Bxa3 {[Pgndiagram] This amazing bihop sacrifice is winning for Black. But  it is bot easy to make it work} 2. Rc3 $1 {The best defence}   (2. bxa3 b2+ 3.  Kxb2 Rb8+ {[pgndiagram] Is easily won for Black})   (2. Nf4 Bxb2+ $1 3. Qxb2   (3.  Kxb2 a3+ 4. Ka1 b2+ 5. Ka2 bxc1=N+ 6. Rxc1 Qb5 {[pgndiagram] And Black has big  material and positional advantage}) 3... Qxe3 4. Nxd5 a3 $1 {[pgndiagram] And  Black wins}) 2... Bxb2+ 3. Kxb2 a3+ 4. Ka1 {[pgndiagram] And now it is not  clear what is the best continuation} Qe4 $1 {Attacking the rook on h1} 5. Rf1  b2+ 6. Ka2 O-O {[pgndiagram] And Black has a winning attack. Ba6-Bc4 will be  deadly in the future} 7. Qf4 Qxf4 8. Nxf4 Ba6 {And there is no defence against  Bc4} *