9. Closed Catalan with 7.b3 and the Ba3 exchange

With 7.b3 White protects c4 and with 8.Ba3 exchanges the dark-squared Bishop, the piece Black uses to defend the dark squares. The a3 Knight will return to the game via c2.

1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.b3 b6 8.Ba3 Bxa3 9.Nxa3

Move by move

1.d4 – White occupies the center with the Queen's pawn: it controls e5 and c5 and prepares c4, the first step of the Catalan.
1...Nf6 – Black develops the Knight and controls e4: it postpones the choice between ...d5, ...e6 and the Indian defenses.
2.c4 – White gains space with the c-pawn: it controls d5 and prepares Nc3 or the g3 fianchetto.
2...e6 – Black opens the f8 Bishop and prepares ...d5: this is the structure of the Queen's Gambit Declined, against which the Catalan is designed.
3.g3 – The Catalan: White prepares the fianchetto on g2, from where the Bishop will aim at d5 and the whole Black queenside.
3...d5 – Black occupies d5: now the g2 Bishop will have a pawn in front of it, but the c4 pawn attacks it and the tension remains.
4.Bg2 – The Bishop settles on the long diagonal: it presses on d5 and, if Black captures on c4, it will hit b7 and a8.
4...Be7 – The Closed Catalan: Black does not take on c4, develops the Bishop and prepares castling, keeping the d5 pawn in the center.
5.Nf3 – White develops the Knight and prepares castling: with the Bishop already on g2 the King will be safe in one move.
5...O-O – Black castles and still leaves the possibility of taking on c4.
6.O-O – White castles: now the Queen and the b1 Knight can support the push e4.
6...Nbd7 – Black develops the Knight on d7 before deciding the structure: it supports ...c5 and ...b6.
7.b3 – White protects c4 with the pawn, so ...dxc4 gains nothing, and prepares Ba3 or Bb2.
7...b6 – Black prepares ...Bb7 and control of the long diagonal.
8.Ba3 – The Bishop goes to a3 and offers to exchange the dark-squared Bishops: Black loses its best Bishop, which defends c5 and e5.
8...Bxa3 – Black exchanges the Bishops: it does not want to leave the a3 Bishop the diagonal toward f8 and the c5 square.
9.Nxa3 – The Knight recaptures on a3: from here it will go to c2 and e3 or to b5, while the dark squares c5 and e5 are left without a Black Bishop.

How to exploit the position

After the exchange of the dark-squared Bishops White plays on the c5 and e5 squares, which Black can no longer defend with a Bishop.

The a3 Knight goes to c2 and then to e3 or b4, where it presses on d5 and c6.
The Queen goes to c1 or d2 and the Rook to c1: the c-file is the point of pressure.
With Ne5 occupy the central square: Black has no Bishop that can drive it away.
If Black pushes ...c5, answer with cxd5 and dxc5 to leave it with isolated pawns.

Master tips

The dark squares

By exchanging the dark-squared Bishops White takes away from Black the piece that defends c5 and e5: the White Knights can use them.