Cambridge Springs Defense

The Cambridge Springs Defense is an active line of the Queen's Gambit Declined. After supporting d5 with ...e6 and ...c6, Black plays ...Qa5, moving the queen from d8 to a5. The move seems to take the queen away from the center, but it performs several concrete jobs.

First, once the queen leaves d8, Black's f6-knight is no longer pinned by White's bishop on g5. A pin occurs when a piece cannot move without exposing the king or a more valuable piece behind it. Second, the queen on a5 pins White's c3-knight to the king on e1 along the a5-b4-c3-d2-e1 diagonal.

...Qa5 breaks one pin and creates another

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StartQa5

The bishop attacks f6 and aligns with the queen on d8 behind the knight. The two arrows form one pin.

The queen still stands behind the f6-knight

Bg5 pins the knight to d8, while ...c6 supports d5 and clears c7 for the queen's route.

1. The bishop attacks f6 and aligns with the queen on d8 behind the knight. The two arrows form one pin.
2. The c6-pawn defends d5 and stabilizes the center before the tactical operation begins.
3. ...Qa5 can follow d8→c7 → b6→a5 because the c-pawn has left c7.
4. From a5, the queen will align with the king on e1 through White's c3-knight.