If Black plays e5 in the Sicilian, it leaves a hole on d5 and f5, and must be justified by piece play. e6, on the other hand, gains less space and allows White more freedom of where to place the pieces. The two moves are typically both found in the Najdorf Sicilian, where e5 is the preferred move in many positions while e6 is played when e5 would leave the hole on d5 weak. An example is the Najdorf with 6.Bg5 when 6...e6 is much better than 6...e5 which allows White to exploit the d5 hole in many variations. 6.Bc4 e6 is another example - here, e5 not only weakens d5 but also f5.
Sicilian defense question

Thanks a lot "expertise87." So e6 may be more flexible but allows white more possibilities in terms like the f4 pawn advance and more space in the center?
...e5 leaves f5 vulnerable to thematic piece sacrifices on f5 as part of White's attack against Black's K-side.
Of much greater importance is the fact that ...e5 destroys the small but secure center formed by Black's pawns at d6,e6, and f7. This bulwark of defense doubles as an alternate castled position for the Black K in the center. It is extremely resilient against the voracious attacks of the White pieces.

good points but its also true that playing najdorf/scheveningen(e6 d6) is a tad harder than pelikan/classical(e5 d6)

@manikcharan, I agree. With e5 and d6, black adopts a central pawn structure right away whereas with pawns on e6 and d6, black must properly time the crucial d5 break.

not saying don't play e6,d6 but its like kaspy(i think) said: "The greater the risk the greater the reward" e5,d6 is just less of a risk i think
The 2 vs. 1 pawn advantage that Black has in the center is a static majority advantage that will endure into the endgame. Steering the game into an equal or winning endgame for Black is the underlying long range strategy. The thematic ...d5 advance is one, admittedly a very important, intermediate stage in steering the game into the balanced or winning endgame for Black.

I wouldn't say its a risk to play e6/d6 because even e5/d6 definitely has setbacks like the weakened f5 and d5 squares.

thats right but you don't get into razor sharp variations like the poisoned pawn, richter rauzer and adams attack(my fav). i play najdorf sicilian and have successfully used it in tournaments. and anyways just my opinion not necessarily true for all, try them all and play what you like not what's best
manikcharan wrote:
thats right but you don't get into razor sharp variations like the poisoned pawn, richter rauzer and adams attack(my fav). i play najdorf sicilian and have successfully used it in tournaments. and anyways just my opinion not necessarily true for all, try them all and play what you like not what's best
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Yes, sound advice, play what makes common sense to you.
In the long run against the strongest opposition you will discover that ...d6, ...e6 is the fulcrum of Black's position. And, you will burn the midnight oil, having to do what I did over many months and years. Today I know 400 variations of the poisoned pawn cold. Playing the White side of the Najdorf against very strong opposition is enlightening and deepens your understanding of the opening.

So the english attack with e5 isn't as sharp as the english attack with e6? I don't honestly believe that, in the richter rauzer / poisoned pawn white decides most of the lines and how sharp they are, etc.
If not poisoned pawn white can chose this sharp line:

you should take a look at the adams attack one very flashy but not outright bad game Fischer vs Najdorf:
i admit najdorf could've played a bit better at many places but this game introduced me to the adams attack

It's still pretty dang sharp . I'm fine with all that Bg5 sharp stuff, but against the english attack I play Ng4.

Against 4. f3 is the best line 4...e5 5. Nb3 d5 (Actually I think it's 5.f3)? I seem to recall something of that sort. Also, I always play my pet line 6...Qb6 against 6. f3, and I am a big fan of the positions that result.
After Ng4 Bc1 Nf6 I usually accept a draw , it's better than being put into an actual english attack accidently. I drew a player 200+ points higher than me this way once, with no effort. Of course, with the new FIDE rules we would have to repeat until like move 40 for the draw to be legal, right?
How does black's playing e6 versus e5 affect the strategy of the play? I know e6 prepares d5 but does playing e5 make white's kingside assault more difficult? Thanks for the help.