Move 4 discussion: Everyone vs stockfish

[MooMoo2]

The poll for move 3 just closed, and the most popular move was Nd2. Stockfish responded with 3...c5, and the FEN is:
rnbqkbnr/pp3ppp/4p3/2pp4/3PP3/8/PPPN1PPP/R1BQKBNR w KQkq c6 0 4

Game so far: 1.e4 e6 2. d4 d5 3. Nd2 c5

[Brian-E]

This variation is usually characterised by Black allowing itself to be saddled with an isolated queen's pawn (after the moves e4xd5, e6xd5 have been played now or very shortly) in exchange for achieving enough space to develop its pieces easily. I think we can be pleased with this, because that isolated black queen's pawn usually means that Black has to sit around defending it well into the middlegame, spoiling its chances of activity.

The two most frequently played moves now are 4.exd5 and 4.Ngf3. (A few other moves are also possible too.) The first one 4.exd5 appeals to me at the moment because it forces Black to declare its intentions at once, either accepting the isolated queen's pawn with 4...exd5 or doing awkward shenanigans with 4...Qxd5 to avoid it.

[LaurV]

[edit: crosspost with Brian, I have this opened for hours, didn't check if new posts, before clicking send]

Well, outvoted. Didn't I say that?

And that is how our chances to win are gone... Some will argue that we didn't have any, in the first place, to which I disagree

Now, there are only two continuations on the table, 4.exd exd, which is 47% chances of a draw (even more, after 5 Ngf3), with under 30% for white win and a bit over 20% for black win. Playing against a computer (which doesn't make blunders) this is draw 100%**, even if we could play perfect from now on. If you ask me (not the database), I would say that black is already better there, he has all lines opened for attack (to develop his pieces) and it has the sente (he is to move after a quite passive Ngf3), during which white is "jailed", no place to move the knight in d2 which stops developing the bishop and the queen, etc, no space for maneuver. Therefore I don't understand that w/d/b=30/50/20 score displayed by the DB. For me feels more like 15/55/30. But again, I am not the opening expert.

The second continuation, 4.Ngf3, seems more promising, but not much, so there is where I should vote, if not for the exchange in the middle. Still thinking to this variant. Maybe 4.Ngf3 cxd4 5.Nxd4 Nc6 6. Nxc6 bxc6 7. e5, which would be "damage control" if black replies cxd4. But this is very tricky and my "free access" of the database won't allow me to go deeper here... grrr... you need to be member to see more moves.

Also. 4.c3 seem good, but after 4...cxd 5 cxd, black has already ~43% chances to win... This is not good.

At first sight, 4.e5 is a no play here, anymore, after 4...Nc6 5.dxc Nxe, or 4...cxd we lose the pawns, and playing against a computer this will be a loss. But we may also play defensive, 4.e5 Nc6 5.Nf3 and still may go to a draw (if perfect play, I always assume perfect play when talking about a draw, which doesn't mean that we play "perfect", it only means that we don't make silly mistakes).

----------
** Edit 2: the formulation "this is draw 100%" should be read like "we can't get better that a draw, in any circumstances, when playing against a chess engine" hehe

[axn]

Apparently N(g)f3 outscores exd5 at all expertise levels... Hmmm...

[science_man_88]

Originally Posted by Brian-E

This variation is usually characterised by Black allowing itself to be saddled with an isolated queen's pawn (after the moves e4xd5, e6xd5 have been played now or very shortly) in exchange for achieving enough space to develop its pieces easily. I think we can be pleased with this, because that isolated black queen's pawn usually means that Black has to sit around defending it well into the middlegame, spoiling its chances of activity.

The two most frequently played moves now are 4.exd5 and 4.Ngf3. (A few other moves are also possible too.) The first one 4.exd5 appeals to me at the moment because it forces Black to declare its intentions at once, either accepting the isolated queen's pawn with 4...exd5 or doing awkward shenanigans with 4...Qxd5 to avoid it.

ngf2 I guess.

[Brian-E]

Just as with the possibility 3.exd5 on the previous move, the relative scoring in practice of 4.exd5 against 4.Ngf3 does not tell the whole story. 4.Ngf3 is more often an attempt to win than 4.exd5, which frequently leads to a more sedate position (very slight advantage to White because of Black's IQP). Therefore in games where 4.exd5 is played, Black is very often the stronger player. That is the likely explanation for the better scoring of 4.Ngf3 in practical games.

[axn]

Originally Posted by Brian-E

Just as with the possibility 3.exd5 on the previous move, the relative scoring in practice of 4.exd5 against 4.Ngf3 does not tell the whole story. 4.Ngf3 is more often an attempt to win than 4.exd5, which frequently leads to a more sedate position (very slight advantage to White because of Black's IQP). Therefore in games where 4.exd5 is played, Black is very often the stronger player. That is the likely explanation for the better scoring of 4.Ngf3 in practical games.

Could be. But I wasn't looking directly at W/D/L figures, but instead looking at the difference between game performance rating and player average rating. I feel like that should automatically account for opponent strength.

[Brian-E]

Originally Posted by axn

Could be. But I wasn't looking directly at W/D/L figures, but instead looking at the difference between game performance rating and player average rating. I feel like that should automatically account for opponent strength.

Yes, maybe. I'm interested. Could you provide the source of your information perhaps? I'm also not quite clear what "game performance rating" is, and maybe the source might make that clear (or you can). Thanks!

[WMHalsdorf]

As tempting as 4.exd5 is I prefer 4.Ngf3. Why exchange material that gain you little if any advantage because you have no developed minor pieces to take advantage of the open files.

[axn]

Originally Posted by Brian-E

Yes, maybe. I'm interested. Could you provide the source of your information perhaps? I'm also not quite clear what "game performance rating" is, and maybe the source might make that clear (or you can). Thanks!

http://chesstempo.com/game-database.html

The section marked Ave/Perf/Max Rating (You can click on the "?" button to see explanation of the statistics). As a crude measure, I checked Perf-Ave for both moves (at various player strength levels), and at all levels, Ngf3 showed a better delta than exd5.

[Brian-E]

Originally Posted by axn

http://chesstempo.com/game-database.html

The section marked Ave/Perf/Max Rating (You can click on the "?" button to see explanation of the statistics). As a crude measure, I checked Perf-Ave for both moves (at various player strength levels), and at all levels, Ngf3 showed a better delta than exd5.

Thanks. It seems indeed that (PerformanceRating - AverageRating) is around 38 for 4.exd5 and around 50 for 4.Ngf3, depending on the rating range selected, as you say.

My preference (after reading everyone's contribution so far) still goes to 4.exd5 for the reason that it leads to the type of position where Black has little active play, and that, I think, is good strategy against a computer.