Good, Positional Opening for Black against e4 and d4?

Just for fun, do something that looks ridiculous, but it's not really, it has positional pluses. Play the Lemming. 1. d4 Na6. Then play c6 and plan to place the knight on c7, it's better than it looks at first positionally. In a closed game the tempo lost to get to c7 isn't as important, and there is a good possibility white may give up the two bishops to double your rook pawns.

see http://www.chesslikeananimal.com/?p=261 for details.

That is a very passive setup, one I'd love to grind.

I guess if you're that optimistic about Black always being able to play a c5 break, then almost any defense to 1. d4 looks good.

Trying to teach beginners to play Nd7 or c5 before playing Nc6 is not an easy thing to do. Moreover, a c5 break often means you have to be comfortable in Isolated Queen Pawn situations. Against a sub-1400, that d-pawn is a sitting duck!

I've tried the Lemming against 1. e4 (I think that's where it is mainly used) but I suppose it'd work just as well against 1. d4 since the next move is almost always 2. e4 or 2. d4 respectively.

I was playing against someone of equal skill, so I got beat in the endgame. But it was a fun position, and it beats grinding out dozens and dozens of Sicilians, Caros, Indian defenses, and Slavs when you're playing at the club, giving yourself a bit of a handicap against a weaker opponent, or not preping for a tournament.

However, it'd be one of the last openings I'd recommend to a beginner.

Man, I love all the responses, thank you!  Been rocking the Sicilian Taimanov hard core in practice for two days now.  Love it.  The wikipedia article on the SD was extremely informative and eye opening.

I'm thinking of taking up the Semi-Slav as my main attack/defense against d4.  I like the pawn structure and the numerous variants are great.  I am really itching to try a ...b5, ...b4 pawn push.  Not terribly happy about the wall my QB keeps bumping against, but the full Slav makes me nervous and will until I get comfortable with the Semi.  Read somewhere the theory on the full slav is 30 moves deep.  Way beyond my boyish intentensions right now.

Someone mentioned that nubs are nervous about Nd7.  Yeah, it's new to me, but I'm willing to try stuff out and take a temporary dip in ELO for a long term boost.  How else are you going to get better?

Make no mistake, the Semi-slav is actually more complex and sophisticated than the Slav proper... You don't need to know any 30-move deep theory to play the Slav, neither at 2000 level, nor at 1400 level

Two things: 

1) A question: why is it that 1. e4 e5 (and maybe 1. d4 d5) will teach beginners more about chess than other openings? 

2) I've been looking at players considered positional, namely (Karpov, Petrosian, Lasker, Capablanca and Botvinnik). With Black they tend to play Caro-Kann, Ruy Lopez, Sicilian, Nimzo Indian, Queen's Indian and French Defense. Based on this (quick) empirical finding, my guess is that these openings are good for positionally inclined players. 

And with White, they tend to play: King's Indian, Ruy Lopez, Sicilian, Queen's Gambit Declined, Queen's Indian, Nimzo Indian and English. This should give a hint as to what works for positional players.

To be honest, I think that e4 e5 d4 d5 advice, while it might be true, may also not be true. Can any of us say we really know that playing those openings will help you the most?

I wouldn't be worried about specific opening choices. Just pick one, play some games with it, then go over your games. Each opening has some different logic to it, (e.g., closed games will feature different plans than open games) but there is always a strategy for you to learn, just a different one each time. I don't think there is necessarily a better strategy to learn first. People tend to recommend the open games because they stress piece development, but then, other positions may teach you things you couldn't learn in an open game.

The logic of what to do in a closed game shouldn't be intrinsically less important than knowing what to do in an open game. Even a beginner can grasp the logic of a closed game: since lines are blocked, and nobody can attack with blocked lines, you need to pay attention to the pawn breaks, and in the meantime you have time to take extra moves to put your pieces on their best squares.

What does help to be studied first are tactics and endgames. Tactics are what we use when we're in a fight; endgames teach us how to work together with our pieces (and pawns too, since they can promote so often) on the most fundamental level. But play whatever opening you want.

But you have to be able to do that in just about every position. Even in closed positions the center can open up.

Let's say you only play "closed" openings (which, of course, can easily result in open positions at some point in the game too). You analyze every game you lose. If you lost a game because you didn't know how to play in the center, wouldn't you be able to analyze that in the games in which you were punished for that?

Elubas, I like your non-dogmatic attitude.  However, I think open positions tend to be more tactical than closed positions, so if working on tactics as a beginner, playing open games might be a good idea.

Against 1.e4 play c6 or e6 ( The Caro-Kaan and French)

Against 1.d4 play e6 orperhaps even Nf6 hoping to get into a Nimzo-Indian.

If you're losing a lot of the time playing as black, my guess is that it isn't the opening you're choosing, rather it's your overall technique. What you should probably do first is put up a game or 2 for us to take a look at because you're either blundering the opening altogether or are having trouble with your middle game.

Plenty of people on here will give you suggestions of openings to play and while pretty much all of them are good ones, you gotta have solid fundamentals first before tackling an opening.

Sicilian kan

Intermediate and advanced players do not bother about crap like the Colle, or Torre, or London.

French and semi slav.

What a broad request...

For 1. e4, you have a variety of options at your disposal. The most popular, of course, is the Sicilian Defense, an opening that may be difficult to learn, but is infinitely rewarding if you can tame the variations. Other options I reccommend include the French Defense, the Caro-Kann Defense, the Pirc Defense, the Scandinavian Defense, and the Angelo-Indian Defense.

As for 1. d4, I reccommend the Indian Defense lines, which include the King's Indian Defense, the Queen's Indian Defense, the Nimzo Indian Defense, and the Bogo-Indian Defense. Other reasonable options include the Benoni Defense, the Benko Gambit, the Slav Defense (and the Semi-Slav), and the Oturo Counterattack.

The Tarrasch defense is good against 1.d4, 1.c4, 1.g3, 1.b3 and 1. Nf3.  It's easy to learn and offers dynamic play.  The pawn structure is simple and the knights are played in alphabetical order, you castle within the first 10 moves and to the kingside (the same as white in most cases, so the odds you're getting checkmated early decrease.)

Caro-Kann hands down.

e4-c5

Is the nimzo-indian and sicilian najdorf positional openings