O'Kelly Variation, Venice System

With 3. c3 White adopts an Alapin setup against the O'Kelly and aims for d4 and a broad pawn center. The argument is that ...a6 has cost Black time while Nf3 has come out at no cost. The two most popular replies are almost equally common. 3...d6, the Steiner Line, concedes the center. After 4. d4 Qc7 the queen steps off the d-file, unpinning the d6-pawn so that dxc5 can be met by ...Qxc5. Black then fianchettoes the king's bishop but has less space. 3...d5 is the standard Alapin reaction. After 4. exd5 Qxd5 White cannot gain time against the queen with Nc3, and the two-pawn center is prevented. Leaving the pawn with 4...Nf6 is the Gambit Line.

3...e6 intends ...d5, and 4. d4 d5 5. e5 gives an Advance French structure. 3...b5, the Ljubojevic Line, continues with ...Bb7 and ...e6 and can transpose into the St. George line of the French. It has given Black fair results. The Barcza Line, 3...Nf6, is rarer and scores worse for Black. The engine assesses the position as close to balanced, and online results slightly favor White.