The line 5.f3 in the Najdorf Sicilan after 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.f3 from Whites point of view. After 5.f3, four main reactions of Black are examined: 1) 5..e5 6.Nb3 but also 6.Bb5 is analysed, then 2) Dragon structures after 5.f3 Nc6 6.c4, where Black now or lates plays g7-g6, 3) Hedgehog schemes after 5.f3 Nc6 6.c4 e6 and finally 4) the lines where Black to avoid 5.f3 continues 1.e4 c5 2.Nf3 d6 3.d4 Nf6 - analysed are both 4.dxc5 and 4.Bb5+. The games contain both analysis and word explanations. Index of variations and Name index in the end. Grandmaster Sergey Kasparov himself plays this line for many years. Further information about the book and a sample are available at newinchess.com