Sicilian Defense: Closed, g3, d6BETA

With Nc3 White has strenghtened their control over the light squares in the center while at the same time blocking their c pawn and giving Black time to improve their control over d4. Usually this implies that White will put their pawns on d3 and f4, aiming to stabilize the center while pushing for a very quick kingside attack. Two setups are about equally popular against most Black replies:

• The Closed Siclian involves a development scheme with early g3, Bg2, Be3, Qd2 before White castles short and pushes the kingside pawns. Separate variations exist based on the placement of the king's knight and the timing of the pawn pushes but strategically, all are based on kingside pressure. The Black counterplay meanwhile is most often based on an attempt to break through on the queenside before White gets anywhere on the kingside.
• The Grand Prix Attack is based on an early f4 in conjunction with developing the bishop outside the pawn chain to c4 or b5. After Nf3 and 0-0, White will usually start a queenside attack with queen maneuvers Qe1-g3 or Qe1-h4 and/or an early f5 pawn push. This setup leads to a quicker attack but is considered less positionally harmonious, therefore Black usually plays to achieve the d5 break in the center as quickly as possible, often prepared with e6 and Nge7.

Both the Closed Sicliain and the Grand Prix have a reputation of being very combative and offering good practical attacking chances but engine analysis has consistently shown that Black has many resources to repel the attack and excellent chances to get an objectively better position with best play. As a result, theory in these lines is not very deep as most White players are advised to deivate early and seek attacking chances in a line that is less known.

One important thing to note is that White has not yet ruled out the Open Sicilian and most popular replies allow them to follow up with 3. Nf3 and 4.d4. The early Nc3 is not much of a commitment and White hopes to lure Black into a variation of the Open Sicilian with which they are not familiar. For a while, this was considered a dangerous move order against players trying to reach the Najdorf Sicilian (1. e4 c5 2. Nf3 d6 3. d4 cxd 4. Nxd Nf6 5. Nc3 a6), as this can't be reached after the most popular Nc6. However, both 2. ...d6 and 2. ...a6 have been proven as viable reactions to any of the described White options with motives similar to the main lines previously described.