ErictheRed wrote on 06/29/15 at 02:22:56:


That last caveat, being sure not to be move-ordered out of your repertoire, is the main reason for studying at least a few Caro-Kann lines if you play the Slav. 

Many Slav players will play 1.c4 c6, but in order to do so, they usually need to know the Panov-Botvinnik (1.c4 c6 2.e4 d5), which is a Caro-Kann opening. It's not necessary to learn the entire Caro-Kann repertoire as a Slav player, but there are some cross over lines. 

There are some who recommend a Tarrasch repertoire, playing QGD Tarrasch lines and French Tarrasch lines. 

In general, I agree that one shouldn't strive to play the same ideas against 1.d4 as against 1.e4, but I do understand why playing similar pawn structures is appealing. Some players go to extremes though, playing Pirc and KID lines or 1...c6 2..g6 against everything. Those players probably stunt their growth by making such limiting choices.

Nimzo + QID (or Bogo-Indian) would come to mind as a combination, where positions can on occasion truly be similar in feel and character. Plus some Caro-Kann lines offer some direct transpositions into Nimzo lines, so in some sense there is a bit of combo feel (plus players like Karpov have combined them), but there's not that many similarities. Also, lines like 1.c4 e5 2.g3 Nf6 3.Nc3 Bb4 (or some similar sequence) may superficially look like the Nimzo Indian, but are very different (perhaps as similar as the Caro-Kann and the Slav?! I guess the Caro-Kann & Slav similarity is non-negligible since in either case there are lines with dxe4 (or dxc4) followed by Bf5, but as others have commented there are also major differences).

Perhaps you could argue that the Ruy Lopez Chigorin variation can have some similarities in terms of black plans with the King's Indian?! But honestly, I think they are very different in character.

You can play "the Sniper" ( Black plays g6, Bg7 and c5) to reach original positions, often by playing Bxc3. Alternatively it gives a chance to transpose into lines of the many mainstream openings where Black plays these moves.

The set up with Nf6, g6, Bg7, O-O is common to a number of openings as is d6, g6, Bg7. So you can mix and match between the Benoni, Kings Indian, Grunfeld, Leningrad Dutch, Pirc or Modern.

I do not believe that this is necessary to have a combination. I play so many defences that they often have no 1:1 correlations. Til example, I play against 1. e4, the Pirc, Sicilian, French, Caro-Kann, Alekhine, and against 1. d4, Grünfeld, Slaw, Nimzo-Indian/Queen's Indian a little bit, and have studied but not played yet the Leningrad Dutch. 

In a tournament, it is like a wheel, I just choose whichever from the list depending on opponent and tournament situation. I never think about which pawn structures correllates with each other. The Slaw and the Caro-Kann and French are related somewhat, but given that I play 1...g6 against both the English and Réti, there is no real coherence in my choices. I just play those openings because I like them.

One well known very good combo is the Caro-Kann + the Slav:

- The main objective of both of these openings is to develop the light-squared Bishop to f5 before it gets locked inside the Pawn chain.
- They tend to lead to roughly similar Pawn structures.
- On average they both tend to lead to positional, quiet and strategic games.
- And most importantly, if you choose both of these openings, against 1. c4 you can play 1...c6 which can transpose into either a Slav (2. d4) or a Caro-Kann Panov/Pseudo-Panov (2. e4).

I would like to know what are all the other possible combinations of openings which work well together.

I am only interested in combos where both openings are sound.

And if possible also explain why exactly the openings work well together.