Modern Defense: Geller's System: Plans and Traps

Key ideas for both sides

White

Bd3, O-O and Re1 build a firm center, as in the top engine line.
h3 takes g4 from Black's bishop, so the f3 knight is never pinned.
a4 answers ...a5 and keeps Black's queenside pawns from advancing.
Against ...Nc6, use Bb5 to pin the knight and keep pressure on e5.

Black

...Nf6, ...O-O and ...Nbd7 prepare ...e5 without allowing tactics on the e-file.
...Nc6 with ...e5 strikes at d4 at once, as in the second engine line.
...a5 gains queenside space and makes b4 harder for White.
If White skips h3, ...Bg4 pins the f3 knight and adds pressure to d4.

Plans and pawn structure

The c3 pawn supports d4, so Black's ...e5 break does not shake the center. White builds with Bd3, O-O, h3 and Re1, then looks at a4 or a later d5 to gain space. Black develops ...Nf6, ...O-O and ...Nbd7, then plays ...e5 and decides between ...exd4 and keeping tension. The game is slow and maneuvering, and White keeps a little more room.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.45: a slight edge for White. Its three top choices for Black:

+0.45 4...Nf6 5.Bd3 O-O 6.O-O Nbd7 7.Re1
+0.48 4...Nc6 5.h3 e5 6.Bb5 Bd7 7.O-O
+0.49 4...a5 5.h3 Nf6 6.Bd3 Nbd7 7.O-O

Pawns, from White's side.

How it scores on lichess

1,866 rated lichess games reached this position; White scored 50.9%.

under 120041.7%

1200–159949.8%

1600–199951.6%

2000 and up54.0%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

How to play against it

As Black, prepare ...e5 carefully with ...Nbd7 or ...Nc6. Use ...a5 to slow White's queenside. Avoid ...exd4 too early, which frees White's c3 knight square and pieces.

Questions

What are the moves of the Modern Defense: Geller's System?

The Modern Defense: Geller's System starts 1.e4 g6 2.d4 Bg7 3.Nf3 d6 4.c3. Its ECO code is B07.

Is the Modern Defense: Geller's System good for White?

Stockfish 17.1 rates the position +0.45 at depth 20, which is a slight edge for White. In 1,866 lichess games from our sample, White scored 50.9%. A low-risk system for White players who like calm positions, with Black getting solid but slightly cramped play.

What is the main idea of the Modern Defense: Geller's System?

White backs up d4 with c3 and develops calmly with Bd3, O-O and h3. Black aims for ...e5 after ...Nf6 and ...Nbd7 or ...Nc6.

What should Black play next?

The engine's first choice is Nf6, with Nc6 and a5 close behind. 4...Nf6 develops and prepares to castle before the ...e5 break.

Updated October 2026. Sources and method.

Modern Defense: Geller's System