Board Position
1.P-QB4(c4) is a relatively modern flank opening that first became popular after its use six times in an 1843 match by top English player Howard Staunton against top French player Pierre Saint-Amant. Board Position
White avoids early centre occupation and often fianchettoes his KB, putting pressure on the Q-side pawns and attacking along the QB-file (move 11, right) once Black plays P-Q4. White is thus often playing the Sicilian Defence with a move in hand, but Black has several good lines.
One advantage for White is the difficulty of transposing the defence into some other opening, although several initial transpositions into Queen's Gambit and QP openings are possible. Immediate variations include the Symmetrical, King's Indian (to Closed), Hedgehog, Anglo-Dutch and English Orang-Utan.
Begin or Clear or Groups or see move: 1 c4 for main lines: e5 2 Nc3 Nf6 to:

Brem: 3 g3 d5 4 cxd5 Nxd5 5 Bg2 Nb6 6 Nf3 Nc6 7 0-0 Be7 8 d3 0-0 9 Be3 Be6 10 Rc1 f6 11 Na4 Qd2
4Kts.: 3 Nf3 Nc6 4 d4 exd4 5 Nxd4 Bb4 6 Bg5 h6 7 Bh4 Bxc3+ 8 bxc3 Ne5 9 f4 Ng6 10 Bxf6 Qxf6