The Old Benoni Defence arises after 1.d4 c5. ECO code: A43.

Overview

The Old Benoni Defence is an ancient defence where Black immediately challenges the d4-pawn from the side. The name "Benoni" comes from the Hebrew "ben oni" meaning "son of my sorrow," coined by Aaron Reinganum in a 1825 book.

Main Lines

After 2.d5, Black has created a Benoni-type pawn structure. The main continuations are:

• 2...Nf6 – Developing a piece, heading toward Modern Benoni structures.

• 2...d6 – Solid, maintaining the Benoni pawn structure.

• 2...e5 – The Czech Benoni, locking the centre.

• 2...f5 – The Mujannah formation, a rare and aggressive try.

Strategic Themes & Plans

Black obtains a Benoni structure with the c5-pawn controlling d4. White's d5-pawn gives a space advantage, and the typical Benoni themes arise: White attacks on the queenside with c4, Nc3, and a potential e4; Black seeks kingside counterplay or a ...b5 break.