What are all the most common transpositions between the Caro-Kann Panov–Botvinnik Attack with 5...e6 6. Nf3 Bb4 and the Nimzo-Indian Defence?

Question

I would like to know what are all the most frequent transpositions between the two following openings:

.

The Caro-Kann Panov–Botvinnik Attack with 5...e6 6. Nf3 Bb4:

  [StartPly "12"]

  [FEN ""]
  1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Bb4

.

The Nimzo-Indian Defence:

  [StartPly "6"]

  [FEN ""]
  1. d4 Nf6 2. c4 e6 3. Nc3 Bb4

.

Please try if possible to provide the list of all the transpositions sorted from the most common to the rarest.

.

Edit: I found two transpositions which seem to be very common ones.

Both of these two lines:

• 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5 6. Nf3 c5 7. O-O cxd4 8. exd4 dxc4 9. Bxc4
• 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5 6. Nf3 c5 7. O-O dxc4 8. Bxc4 cxd4 9. exd4

Transpose into this line:

• 1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Bb4 7. Bd3 dxc4 8. Bxc4 O-O 9. O-O

But there are maybe more transpositions.

Answer 1

There are indeed a couple of transpositions from the Nimzo-Indian to the Panov variation of the Caro-Kann and they occur sometimes in practical games.

Using a database of chess games, they can be filtered by searching simultaneously on:

1. The position after 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4
2. "B10-B19", i.e. the ECO-code of the Caro-Kann.

After finding the games where an actual transposition occured, they can be put in a tree-like structure to count the transpositions.

Using ChessBase Mega Database 2015, 91 games are found, for which both players have a FIDE rating of 2200 or more. Then, the found games were put in a ChessBase tree-file (.ctg).

The most common transpositions found this way are:

1. 4.e3 0-0 5.Bd3 c5 6.Nf3 d5 7.0-0 cxd4 8.exd4
2. 4.e3 0-0 5.Bd3 d5 6.Nf3 c5 (see 1)
3. 4.e3 c5 5.Nf3 0-0 6.Bd3 (see 1)
4. 4.e3 c5 5.Bd3 0-0 (see 1)