E00-E99

The starting point of the 4.e3 O-O variations. White maintains maximum flexibility before committing to a specific central structure.

The Nimzo-Indian with 5.Nf3. White develops naturally to maintain the balance and keep all options open for the middle-game.

The Nimzo-Indian with 5.Nf3 b6. Black uses the Queen's Indian setup to bolster the e4-control within the Nimzo framework.

A sharp tactical branch where Black challenges d4 with c5. It leads to open play where piece coordination is the deciding factor.

The Nimzo-Indian with 5.Nf3 c5 6.e3. White accepts an isolated queen's pawn for active piece play and attacking chances.

The main line of the IQP Nimzo-Indian. A highly technical struggle where White's activity is pitted against Black's structural solidity.

The Nimzo-Indian with 5.Nf3 O-O 6.Bd3 d5. A classical setup for both sides, leading to a balanced and deeply strategic middle-game.

Refinements of the d5 Nimzo. Both players engage in a slow maneuvering battle for control of the key central squares.

The main theoretical line of the 6.Bd3 d5 Nimzo. White maintains a slight space advantage while Black holds a very resilient position.

The final theoretical refinement of the 4.e3 Nimzo-Indian. It is a masterpiece of modern strategic and tactical analysis.