Steinitz Defense

The Steinitz Defense, 3...g6, is one of Black's ways of avoiding the Four Knights Game after 3. Nc3. Instead of developing the king's knight, Black prepares ...Bg7, placing the bishop behind the e5-pawn on the long diagonal. The setup is slower than ...Nf6 followed by a single bishop move, because the fianchetto takes an extra tempo, and the engine gives White a slight edge. The name comes from Steinitz's win over Rosenthal in 1873. That game reached the same setup by the move order 2. Nc3 Nc6 3. Nf3 g6, and continued 4. d4 exd4 5. Nxd4.

The main theoretical test is 4. d4, which opens the center before the bishop reaches g7. After 4...exd4, White can recapture as Rosenthal did, or play 5. Nd5, the Steinitz-Rosenthal Variation, which leaves the pawn alone and puts the knight on an advanced central square instead. Online, the most frequent choice is 4. Bc4, aiming at f7, followed by 4. d4 and 4. Bb5, which puts Ruy Lopez-style pressure on the c6-knight. Results across these lines are fairly close, with White scoring somewhat better after 4. d4.