Catalan Opening

The Catalan is a chess opening where White adopts a combination of the Queen's Gambit and Réti Opening: White plays d4 and c4 and fianchettoes the white bishop on g2. A common opening sequence is 1.d4 Nf6 2.c4 e6 3.g3, although the opening can arise from various move orders (see transposition). "Encyclopaedia of Chess Openings" ("ECO") codes E01–E09 are for lines with 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2, and others are part of E00.
Black has two main approaches to choose between: in the Open Catalan Black plays ...dxc4 and can either try to hold on to the pawn with ...b5 or give it back for extra time to free their game. In the Closed Catalan, Black does not capture on c4; their game can be somewhat for a while, but is quite .
The Catalan is generally seen as a safe way for White to get a small advantage.
History.
The Catalan derives its name from Catalonia, after tournament organisers at the 1929 Barcelona tournament asked Savielly Tartakower to create a new variation in homage to the area's chess history. It had been played a few times before Tartakower's usage in the tournament, however: Réti–Leonhardt, Berlin 1928, for instance, transposed into an Open Catalan. The opening cemented itself in the repertoire of leading players of the thirties and forties, such as world champions Jose Raul Capablanca, Alexander Alekhine & Mikhail Botvinnik as well as top grandmasters such as Salo Flohr, Paul Keres & Samuel Reshevsky.
The Catalan came to prominence at the top level when both Garry Kasparov and Viktor Korchnoi played it in their Candidates Semifinal match in London in 1983: five games of the eleven-game match were Catalans.
In 2004, Ruben Felgaer won a tournament celebrating the 75th anniversary of Barcelona 1929 and the birth of the Catalan Opening, ahead of Grandmasters (GMs) Viktor Korchnoi, Mihail Marin, Lluis Comas and Viktor Moskalenko and International Master Manel Granados. Each game in the tournament, which was also held in Barcelona, began with the moves 1.d4 d5 2.c4 e6 3.g3 Nf6.
With its use by Vladimir Kramnik, the Catalan has gained a good deal of attention by high-level GMs in recent times. Kramnik played the opening three times in the World Chess Championship 2006. The Catalan was also played four times by Viswanathan Anand in the World Chess Championship 2010; in both instances the opponent was Veselin Topalov, and in each instance White scored two more points than Black.
Open Catalan, Classical Line.
The Open Catalan, Classical Line begins 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 dxc4 5.Nf3 Be7. White trades the pawn for a lead in . Without the d5-pawn, White's bishop hinders Black's development. The Open Catalan line has been a favorite of Anatoly Karpov and Efim Geller as Black and Oleg Romanishin with the white pieces. Usually, White will recover the pawn with Qc2 and a4, Ne5, or Qa4. In order to hold the pawn, Black will have to seriously weaken the queenside with ...a6 and ...b5. The "ECO" code is E05.