2
[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5?!

Why is ...e5 considered dubious for Black here, although it is considered sort of a refutation after the move 5.f3?! e5!

What's the big difference? If it is strong after 5.f3, it shouldn't be so bad after 5.Nc3, the pawn structure is the same.

Glorfindel
  • 24,745
  • 6
  • 67
  • 114
A. N. Other
  • 6,816
  • 2
  • 28
  • 66
  • 1
    A couple of months ago, a similar question has been asked: http://chess.stackexchange.com/questions/12246/whats-wrong-with-4-e5-in-the-open-sicilian/12248#12248 Also in this position 6.Bb5+ seems to be very strong. – Maxwell86 Feb 05 '16 at 16:47

2 Answers2

3

The problem with e5 is that after 6.Bb5+ white will be able to play the manoeuvre Nf5-Ne3 which will result in an iron control of the d5-square. (Without Bb5 the knight on f5 could be taken by the Bc8).

The difference to the 5.f3 line is, that f3 doesn't control d5, so when the knight lands on f5 the counterstrike d5 will be possible.

[fen ""]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5?! 6. Bb5 Bd7 7.Bxd7 Qxd7 8. Nf5
BlindKungFuMaster
  • 19,178
  • 1
  • 47
  • 77
  • To add to that, playing an early ...e5 in some variations of the Najdorf is a dynamic move because it immediately makes a play for the initiative, forcing White's knight out of the center. If black allows Bb5 in that position, it just cedes initiative and lets white develop while black has to start making defensive moves/grovel. – rougon Feb 06 '16 at 14:29
-2

After Nf5 the d6 pawn will be weak.

Glorfindel
  • 24,745
  • 6
  • 67
  • 114
user9472
  • 1