Ragozin Defense

The Ragozin Defense grows from a Queen's Gambit Declined structure: Black keeps a pawn on d5 supported by the e6-pawn, develops the g8-knight to f6, and places the f8-bishop on b4. That bishop attacks White's knight on c3 and pins it to the king on e1, meaning that moving the knight would expose a line of attack against the king.

The pin has a strategic purpose. The c3-knight attacks d5 and controls e4; by pinning and potentially exchanging it, Black restricts a central piece and can remove one attacker of d5. If Black's bishop captures the knight on c3 with check and White recaptures with the b-pawn, White is left with two pawns on the c-file. That structure can become a weakness, although White keeps both bishops and gains a more open b-file in return.

...Bb4 pins an active central piece

1

2

3

4

5

6

7

h8

g

f

e

d

c

b

a

StartBb4

...Bb4 develops the f8-bishop with an attack on c3. The route and target form one active idea.

The f8-bishop can develop with pressure

The diagonal to b4 is clear, allowing the bishop to attack the knight involved in the fight for d5 and e4.

1. ...Bb4 develops the f8-bishop with an attack on c3. The route and target form one active idea.
2. The c3-knight attacks d5 and controls e4. The two squares show one central function of that piece.
3. ...c5 is an additional break against d4. It is distinct from the pin and keeps its own marker.

The Ragozin combines solid pawns with active piece pressure. It should not be confused with the Chigorin Defense. In the Chigorin, the b8-knight develops early to c6 and Black does not support the d5-pawn in the same way with a pawn on e6, so the central fight begins from a different foundation.