Accelerated Dragon lines: 6...c5 Positionally, 6...c5 is Black's most natural break, attacking the White centre with a side pawn and leaving the a1–h8 diagonal open for the bishop on g7. The most obvious drawback is that 6...c5 loses a pawn to 7.dxc5 dxc5 8.Qxd8 Rxd8 9.Bxc5, and for this reason 6...c5 was previously thought to be impossible. However, Valery Chekhov began exploring the line as a deliberate gambit, and the line is now considered to give Black full compensation. The compensation Black has for the pawn includes: The King's Indian bishop has an open long diagonal. Black has a lead in development, with four pieces in play. White's development has been hindered with the pawn placement on f3. White has a hole on d4 as well as other good targets for Black's knights. A possible practical drawback to the gambit is that White is more or less able to force a draw against Black's best lines, e.g. after 9.Bxc5 Nc6 10.Nd5 Nd7 11.Bxe7 Nxe7 12.Nxe7+ Kf8 13.Nd5 Bxb2 14.Rb1 Bg7 15.Nh3 Nc5 16.Ng5, when Black should allow the repetition of position by 16...Kg8 17.Ne7+ Kf8 18.Nd5 Kg8. The gambit is rarely accepted in contemporary grandmaster play; instead the main line is to head for a Benoni-type structure with 7.Nge2 followed by 8.d5, which frequently transposes to the Kapengut Variation of the Modern Benoni. However, after 7.Nge2, 7...cxd4 8.Nxd4 Nc6 transposes into the Accelerated Dragon variation of the Sicilian Defense, featuring a Maróczy Bind. Byrne Variation: 6...c6 and 6...a6 Robert Byrne developed a flexible approach where Black plays ...c6 and ...a6 in order to prepare the push ...b5. Black's direct counterstrike in the centre is postponed so that the queenside advance can proceed quickly. White can decide to halt Black's ...b5 break by playing 7.a4 at the cost of weakening the dark squares on the queenside. After 7...a5, Black has gained control over the b4-square, and will usually win the c5-square as well. White has other lines that allow Black to play ...b5. 7.Qd2 usually intends queenside castling. 7.c5 (or 7.Nge2 a6 8.c5) is a positional line, aiming to clamp down on the queenside and gain control over the b6-square. Probably the most popular response to the Byrne is 7.Bd3 aiming for a speedy mobilization of the kingside pieces, but allowing Black to proceed with the ...b5 plan. White's prospects of gaining an initiative on the kingside means that Black often