Three Knights Variation, Burille Variation

The Burille Variation, 5. e3, is the restrained branch of the Three Knights Variation. White props up d4 with a pawn and does not try to build a broad center with e4. The cost is that the c1-bishop stays behind the pawn chain, and Black's fianchettoed bishop meets a closed, solid wall. Black usually castles first with 5...O-O, by far the most common reply. White then picks between 6. Bd3, the Paris Variation, and 6. Qb3, the Vienna Variation, which presses on d5 and b7. Less often Black plays 5...c6, keeping a Slav-like hold on d5, or 5...dxc4, giving up the center in return for quick development and pressure against d4.

A named offshoot, the Reversed Tarrasch, is reached from a ...c5 move order: 1. d4 Nf6 2. c4 c5 3. e3 g6 4. Nc3 Bg7 5. Nf3 O-O 6. Be2 cxd4 7. exd4 d5 8. O-O Nc6. It produces a Tarrasch-type structure with the colors reversed. The engine rates 5. e3 as roughly balanced, and Black scores slightly better than White in Lichess games.