...Qxg5) 10.Bxf6 cxd3! (a zwischenzug) 11.Qxd3 Nxf6 wins a piece for Black. Exchange Variation: 4.cxd5 exd5 (1.d4 d5 2.c4 e6 3.Nc3 Nf6) 4. cxd5 exd5 5. Bg5 c6 6. Qc2 and White has a pawn majority in the centre, Black has a pawn majority on the . This pawn structure gives White the opportunity to either advance his pawns in the centre by means of Nge2, f2–f3, followed by e2–e4, or play for a by means of the plan Rb1, followed by b2–b4–b5, then bxc6 in order to create a weak pawn at c6. While Black can play ...cxb5, or recapture on c6 with a piece, each of these possibilities is even less desirable than the backward pawn in the open file. For Black, exchanging at d5 has released his light-squared bishop and opened the e-file, giving him the use of e4 as a springboard for central and play. While chances are balanced, Black is usually more or less forced to use his superior activity to launch a piece attack on White's king, as the long-term chances in the QGD Exchange structure favour White. The following games are model games for White: Central pawn advance: Carlsen vs. Jakovenko, Nanjing 2009 Minority attack: Evans vs. Opsahl, Dubrovnik 1950 Three Knights Variation: 4.Nf3 The Three Knights Variation of the Queen's Gambit Declined is usually reached from the move order 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3, played to avoid the Nimzo-Indian Defense (from the white point of view) and the Exchange Variation of the Queen's Gambit Declined (from the black point of view). Black has a few options in response to the Three Knights Variation. Vienna Variation: 4...dxc4 The Vienna Variation occurs after black plays 4...dxc4 in the Three Knights Variation. The main line of the Vienna continues as 5.e4 Bb4 6.Bg5. White's pawns or pieces occupy the central squares in exchange for long-term pawn structure weaknesses. An instance of Vienna Variation played at the highest level was Fine–Euwe, AVRO 1938. The Quiet Variation of the Vienna Variation occurs after 5.e3. Semi-Tarrasch Defense: 4...c5 The Semi-Tarrasch Defense occurs after black plays 4...c5 in the Three Knights Variation. An important line in this variation is the Endgame Line where the game continues: 5.cxd5 cxd4 6.Qxd4 exd5 7.e4 dxe4 8.Qxd8+ Kxd8 where the queens get traded off in a similar fashion to the Endgame in the Berlin Defense, resulting in a drawish position. This