A brand new chess opening

Mark's opening

1 d4 Nf6
2 Nc3 d5
3 Bf4

As the early development of the queen's knight prevents the move c4, you would be well advised to play e4 if possible, and aim to develop your pieces quickly. The 2nd and 3rd white moves can be played the other way round, as can black's 1st and 2nd move; after 1 d4 d5 2 Bf4, 2 ... c5 is more likely, which makes 3 Nc3 rather an unwise move though.
Also, when playing this opening, watch out for attacks on the pawn at b2.
The main line continues

3 ... Bf5
4 Nf3 e6
5 e3 Bd6
6 Bd3

6 Ne5 is a sound alternative move here too. Assuming 6 Bd3, the main line continues

6 ... Bxf4
7 exf4 Bg4
8 h3 Bxf3
9 Qxf3 0-0
10 0-0 Qd6
11 Ne2 c5
12 c3 Nbd7
13 Rfe1

Variations (white can usually play exactly the same first 6 moves):
Alternative 5th moves for black:

Variation 5

5 ... Bb4
6 Bd3 Bxc3+
7 bxc3

White can later play c4 to get rid of the doubled pawns.

Variation 5.1

5 ... c5
6 Bd3 Bxd3
7 Qxd3

or...
Variation 5.15

6 ... cxd4
7 Nb5

Alternative 4th moves for black:

Variation 4

4 ... c5
5 e3 Nc6
6 Bb5 (or Bd3)

or...
Variation 4.05

5 ... cxd4
6 Nb5


Alternative 3rd moves for black:


Variation 3


3 ... Nc6


4 e3 and then 5 Nf3 works OK here...


4 e3 Bf5
5 Nf3 e6
6 Bd3


But I think Nf3 and e3 the usual way round works slightly better

Variation 3.1


3 ... Nc6
4 Nf3 Bg4
5 e3 e6
6 Be2 Bd6
7 Ne5 Bxe2
8 Qxe2 Bxe5
9 Bxe5 Nxe5
10 dxe5 Nd7

White can then play f4 and castle.



Variation 3.2


3 ... Bg4
4 Nf3 Nc6

which transposes into the above variation, variation 3.1.

Variation 3.3

3 ... g6
4 Nf3 Bg7


transposes into the Grunfeld reversed/symmetrical variation.


Variation 3.4


3 ... c5


Here, I think playing e3 and Nf3 the other way round is best


4 e3 e6
5 Nf3 Be7
6 Bb5 or Bd3