Originally posted by Mark Adkins
After 1. d4 Nf6 2. c4 Nc6 3. Nf3 e6 4. g3 Bb4+ Black is playing a Bogo-Indian anyway. I'm not sure whether this is better for White or Black statistically: the RHP games database (Master games) shows a definite edge for White; the online chessgames.com database shows Black having the edge; chesslab.com shows White with an edge.

Or black plays 4. ..d5! and enters a really sharp line of the catalan (with Nc6).

Originally posted by Mark Adkins
...The point being, you don't want to come up with an opening that depends on your opponents playing weak moves simply because they are unfamiliar with the opening...

...A better question is, does it appeal to your playing philosophy and style? ...

I agree with this poster. Find something that fits your style: aggressive, tactical, positional, or strategic. See this "help" from the Exeter Chess Club's site:

...
* Playing Black against 1. d4
o Playing aggressively as Black against 1. d4
+ Tarrasch Defence, Budapest Gambit, Benko/Benoni, King's Indian, Grunfeld

o Playing solidly as Black against 1. d4
+ Slav Defence, Queen's Gambit Declined e.g. Tartakower, Nimzo/Queen's Indian
...

The full article is here: http://www.exeterchessclub.org.uk/Openings/4choices.html

Originally posted by ChessJester
What do you think about this?

Game 2025009

I've won with it 2 out of 2 times... but what is this opening called?

Anyone care to analyze?

Edit, If white were to go 2. e4 then black can play the french, 2... d5

That's the Horwitz defense up until b6

Originally posted by Mahout
The opponent playing weak moves is the cause of my problems in learning a new opening for OTB from studying a book. It's the slightly weaker moves - the ones that aren't shown in the book because they are weak - that I find so difficult to prepare for.

I don't own any opening monographs, but a good one should present more than just the main lines. When you say "book" do you refer to monographs (specializing in one opening) or to general chess books which have relatively brief sections dealing with a variety of openings?

However, a good opening book should also explain the ideas behind the opening, both for yourself and your opponent. This allows you to plan general goals (e.g., control of a key space, rank, file or diagonal, or making your bishops (or knights) superior, etc., etc.). That way, when your opponent does something unexpected, you can ask yourself whether this interferes with your plans and has to be countered or stopped, or whether you can ignore this. Some unusual moves may not be "to the point" in an opening, but others will say something about the opponent's plans, and you must decide what that is and how to integrate this into your own plans.

Another useful tip is to check the game databases during a game. In particular, chessbase.com will allow you to move the pieces to reach any position and then do a search showing the kinds of games resulting from that position. (RHP has a good game database too, but it's basically a move database until you reach a move sequence which identifies a unique game.) You can also filter the search results by specifying the minimum rating of one or both players. By looking at these games you will often get some idea of where your opponent may be going with a particular move, and how various replies to it work (or not).

However, "playing by database" when you don't understand what is going on, especially beyond the opening sequence, is tedious. Develop a plan, based on what the position offers you vs. your opponent. Then try to make all of your moves go toward making use of your advantages while denying your opponent counterplay. That is, try to figure out what your opponent wants to do, and prevent him from doing it, while improving your own position. And, while doing this, be sure to look out for tactical opportunities (e.g., sacrifices, etc.) for yourself and your opponent.