The Franco-Benoni Defence is a line that initially looks like a French, but then diverges: 1.e4 e6, 2.d4 c5!?. This line is always suggested by beginners, but not even hardly mentioned in the openings textbooks of the masters. This is a little odd, since the lines is actually quite fine. Whats the worst that White can do? Get to the lines in the Old Benoni? Force Black to actually play the French Defence? None of those options sound that bad for Black!
Diagram: Franco-Benoni Defence
This opening line can actually be played against either 1.e4 or 1.d4.
One of the reasons that Grandmasters dont play this line is that its like an Old Benoni if White plays d5. White can choose to play some of the more aggressive anti-Benoni lines that Grandmasters would want to avoid as Black: the Four Pawns Attack Benoni (f4) and the Mikenas Benoni (Bb5+).
Transposition from Smith-Morra Gambit: The Franco-Benoni can arise by transposition from a Morra Gambit (a White gambit against the Sicilian Defence with moves 1.e4 c5, 2.d4!?), should Black choose to play 2..e6 instead of 2..c5xd4.
Transpositions: The line has a whole host of possible transpositions into other openings:
- Benoni: if White pushes 3.d5 and then plays c4, we get to the usual Benoni lines.
- Old Benoni: if White pushes 3.d5 but then avoids playing c4. Usual move order is 1.d4 c5!?
- Sicilian Defence (e6 Sicilian variation lines): if white plays 3.Nf3
- French Defence (Advance French): if White plays 3.c3, Black plays 3..d5 and then 4.e5.
- Sicilian Defence (c3 Sicilian): if white plays 3.c3, but Black avoids the French Defence lines by avoiding 3 d5.