Chess Openings Lab
a8b7c6d5e4f3g2h1

Modern Defense: Two Knights Variation, Suttles Variation

The Suttles Variation is 3...c6 4.Nf3 d6, where Black combines ...c6 and ...d6 for a flexible Modern setup. Black wants ...b5 or ...Bg4 next, while White stops queenside expansion with a4 and develops calmly with Be2, O-O and h3.

Moves
1.e4 g6 2.d4 Bg7 3.Nc3 c6 4.Nf3 d6
ECO
B06
Engine
+0.72 · a slight edge for White (Stockfish 17.1, depth 20)
Played
805 games in our lichess sample
White scores
52.7%

Key ideas for both sides

White

  • 5.a4 stops ...b5 at once, as in the top engine line.
  • Be2, O-O and h3 complete a solid setup, then Re1 or Be3.
  • If Black plays ...d5, push e5 and gain space; the knight on e4 can be chased by Bd3.
  • Keep the center flexible; d5 or e5 only after Black commits.

Black

  • ...b5 gains queenside space if White delays a4.
  • ...Nf6, ...O-O and ...Nbd7 prepare ...e5, the classical break.
  • ...Bg4 pins the f3 knight and adds pressure on d4.
  • ...Qc7 or ...Qb6 support the queenside and pressure b2.

Plans and pawn structure

White plays a4 to restrain ...b5, then castles and builds with Be2, h3 and Be3. Black develops with ...Nf6, ...O-O and ...Nbd7, then plays ...e5. If White pushes d5, Black uses ...c5 or ...cxd5 to open the c-file. The game is slow and flexible.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.72: a slight edge for White. Its three top choices for White:

  1. +0.72 5.a4 Nf6 6.Be2 O-O 7.O-O Nbd7
  2. +0.68 5.Be2 Nf6 6.O-O O-O 7.a4 Nbd7
  3. +0.59 5.h3 Nf6 6.a4 O-O 7.Be2 d5

Pawns, from White's side.

How it scores on lichess

805 rated lichess games reached this position; White scored 52.7%.

1200–159950.3%
1600–199954.2%
2000 and up50.6%

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

How to play against it

As White, play a4 early to stop ...b5. As Black, prepare ...e5 or ...b5 carefully.

Questions

What are the moves of the Modern Defense: Two Knights Variation, Suttles Variation?

The Modern Defense: Two Knights Variation, Suttles Variation starts 1.e4 g6 2.d4 Bg7 3.Nc3 c6 4.Nf3 d6. Its ECO code is B06.

Is the Modern Defense: Two Knights Variation, Suttles Variation good for Black?

Stockfish 17.1 rates the position +0.72 at depth 20, which is a slight edge for White. In 805 lichess games from our sample, White scored 52.7%. A flexible system for Black players who like slow positions; White keeps a small edge with simple development.

What is the main idea of the Modern Defense: Two Knights Variation, Suttles Variation?

Black uses ...c6 and ...d6 for a flexible setup aiming at ...b5 or ...e5. White stops ...b5 with a4 and develops calmly.

What should White play next?

The engine's first choice is a4, with Be2 and h3 close behind. 5.a4 stops ...b5 and keeps Black's queenside quiet.

Updated October 2026. Sources and method.