Board Position
One of the "Orthodox Queen's Gambit (qv.) Declined" Defences commonly identified by 2..P-K2. The particular 6..QKt-Q2 branch (move 6b, left) was christened "The Orthodox" by Dr. Tarrasch in the early 20th Century in contempt for its relative timidity by comparison with his Tarrasch Defence (qv.) (which tends, along with the Slav (qv.) and Semi-Slav (qv.), to be more popular).
Immediate alternatives to the Orthodox are the Lasker (qv.) and Neo-Orthodox Defences. The most favoured continuations are the Classical 7.R-B1 and the Rubinstein 7.Q-B2.
The Classical tends to lead to the Capablanca Freeing Manoevre (..QPxBP, ..Kt-Q4 enabling ..P-K4).

Begin or Clear or Groups or see: 1 d4 d5 2 c4 e6 3 Nc3 Nf6 4 Bg5 Be7 5 e3 0-0 6 Nf3 Nbd7
to Classical: 7 Rc1 c6 8 Bd3 dxc4 9 Bxc4 Nd5 10 Bxe7 Qxe7 11 0-0 Nxc3 12 Rxc3 e5 13 dxe5 Nxe5
to Rubinstein: 7 Qc2 h6 8 Bh4 c5 9 cxd5 Nxd5 10 Bxe7 Qxe7 11 Nxd5 exd5 12 dxc5 Nxc5