King's Indian Defense: Orthodox Variation, Modern System

The King's Indian Defense: Orthodox Variation, Modern System is a solid and aggressive chess opening that leads to a complex middlegame with chances for both sides.

In this opening, Black allows White to establish a strong pawn center with pawns on d4 and e4, while focusing on developing their pieces to prepare for a counterattack. Black's pawn structure is typically flexible, with pawns on d6, e5, and g6, and the dark-squared bishop fianchettoed on g7. White's pawn on d5 often restricts Black's knight on c6, forcing it to retreat to e7.

In the Modern System, White's knight on f3 is moved to d2, aiming to support the pawn center and potentially prepare for a pawn break with f4. This move also frees the f3 square for the bishop, which can be useful in some lines. Black's main plan is to play for the f5 pawn break, challenging White's center and opening lines for their pieces.

Both sides have their own trumps in this opening. White enjoys more space and a strong pawn center, while Black has a solid position and potential counterplay on the kingside. The resulting middlegame positions are often sharp and double-edged, with both players needing to be well-prepared and alert to tactical opportunities.

Overall, this opening is a fascinating and challenging choice that can lead to exciting battles on the chessboard.