Blackmar-Diemer Gambit: ECO D00
"Chess is ruthless. You have to be prepared to kill someone."
- GM Nigel Short (1965 - ?)
Introduction
If you're like me, there is little more satisfying in a rated game of chess than a look of disbelief, confusion, anger, or betrayal on your opponent's face as a result of some move you made--particularly in the opening. It generally signifies that they were completely unprepared for your move, and in addition to the obvious psychological edge, you've yanked them out of book and they have to play by ear from here on out. With certain gambits, you can often get that look as early as move 2. This is one of those gambits.
Affectionately called the BDG by enthusiasts, and named for Armand Edward Blackmar and the notorious Emil Josef Diemer, the Blackmar-Diemer Gambit is a slightly dubious, highly transpositional, and unusually popular (in certain circles) gambit in chess that supposedly begins with the book moves 1. d4 d5 2. e4!.
"But, gitm," you say, "You've never written about a queen's-pawn opening!" Nor do I intend to start now, since I don't play them. Any 1. d4 enthusiasts may look below to the main lines section, where you'll find the BDG main line can also arise from the Scandinavian Defense with 1. e4 d5 2. d4. Fortunately, you can use this flexible opening system with either, and better yet, against some of the more annoying defenses for black.
Note: This writeup is not intended as an exhaustive treatment of this opening, as that would take many, many books. It's a survey of a few primary lines and their respective ideas so that one can make an educated decision as to whether to add the BDG to their repertoire. As always, all annotation herein is mine.
Definition
After 1. e4 d5 2. d4! (or 1. d4 d5 2. e4 if you're into that) (Diagram 1), we're not quite at a BDG, but there are three reasonable replies for black, so they should be covered.
Diagram 1: After 2. d4
+---+---+---+---+---+---+---+---+
|BR |BN |BB |BQ |BK |BB |BN |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP |BP | |BP |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | | | | | | | | 6
+---+---+---+---+---+---+---+---+
| | | |BP | | | | | 5
+---+---+---+---+---+---+---+---+
| | | |WP |WP | | | | 4
+---+---+---+---+---+---+---+---+
| | | | | | | | | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | |WP |WP |WP | 2
+---+---+---+---+---+---+---+---+
|WR |WN |WB |WQ |WK |WB |WN |WR | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
- 2. ... dxe4
This will continue to the main lines covered below.
- 2. ... e6
Look familiar? It should. Black has sneakily transposed into a French Defense. You should bring out the big guns with 3. c4 for a Diemer-Duhm Gambit or 3. Be3 for an Alapin-Diemer Gambit. Read those writeups for more information, as they're outside the scope of this one.
- 2. ... c6
This is a textbook Caro-Kann, albeit arising from a different move order. Fortunately, it's one of the openings the BDG is useful against, so look for it under the Caro-Kann section below.
Major Lines
- Main Line Accepted: 2. ... dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3
As you can see in Diagram 2, white has traded a pawn for a marked increase in development, central control, and open lines. This tends to lead toward a fast-paced attacking game.
Diagram 2: After 5. Nxf3
+---+---+---+---+---+---+---+---+
|BR |BN |BB |BQ |BK |BB | |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP |BP | |BP |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | | | | |BN | | | 6
+---+---+---+---+---+---+---+---+
| | | | | | | | | 5
+---+---+---+---+---+---+---+---+
| | | |WP | | | | | 4
+---+---+---+---+---+---+---+---+
| | |WN | | |WN | | | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | | |WP |WP | 2
+---+---+---+---+---+---+---+---+
|WR | |WB |WQ |WK |WB | |WR | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
You can often expect one of two replies from here, but there are so many ways this position can go, that you really need a sharp tactical eye to play this position. The two main replies follow.
- 5. ... Bg4 6. h3
You should be aware that this is black's strongest reply and at master level black does very well, particularly if they blow open the kingside with Bxf3. However, in club play anything can happen anywhere in the game, and you're still in the opening, so don't worry overmuch. If black takes the knight, capture it with your queen, if they retreat the bishop, charge with g4! to get space and tempo. Remember, in a gambit, a tempo is as valuable as a bar of solid gold. Don't squander them--build upon them, or you'll end up facing the music for your pawn sacrifice.
Diagram 3: After 6. h3
+---+---+---+---+---+---+---+---+
|BR |BN | |BQ |BK |BB | |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP |BP | |BP |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | | | | |BN | | | 6
+---+---+---+---+---+---+---+---+
| | | | | | | | | 5
+---+---+---+---+---+---+---+---+
| | | |WP | | |BB | | 4
+---+---+---+---+---+---+---+---+
| | |WN | | |WN | |WP | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | | |WP | | 2
+---+---+---+---+---+---+---+---+
|WR | |WB |WQ |WK |WB | |WR | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
- 5. ... e6 6. Bg5
In Diagram 4 black has opened up diagonals for his dark-square bishop and queen and put pressure on the d5 square, and you have pinned their knight while developing a piece. Good for you! From here the game typically continues with 6. ... Be7 7. Bd3 Nbd7 8. O-O (Diagram 5) and you're fully developed minus getting your queen off the back rank to connect your rooks while black has not castled yet and their light-square bishop is stuck behind pawns and pieces. Charge!
Diagram 4: After 6. Bg5
+---+---+---+---+---+---+---+---+
|BR |BN |BB |BQ |BK |BB | |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP |BP | | |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | | | |BP |BN | | | 6
+---+---+---+---+---+---+---+---+
| | | | | | |WB | | 5
+---+---+---+---+---+---+---+---+
| | | |WP | | | | | 4
+---+---+---+---+---+---+---+---+
| | |WN | | |WN | | | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | | |WP |WP | 2
+---+---+---+---+---+---+---+---+
|WR | | |WQ |WK |WB | |WR | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
Diagram 5: After 8. O-O
+---+---+---+---+---+---+---+---+
|BR | |BB |BQ |BK | | |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP |BP |BN |BB |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | | | |BP |BN | | | 6
+---+---+---+---+---+---+---+---+
| | | | | | |WB | | 5
+---+---+---+---+---+---+---+---+
| | | |WP | | | | | 4
+---+---+---+---+---+---+---+---+
| | |WN |WB | |WN | | | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | | |WP |WP | 2
+---+---+---+---+---+---+---+---+
|WR | | |WQ | |WR |WK | | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
- Gambit Declined
There is no standard way that this gambit is declined and there are many ways to satisfactorily decline it, as pretty much any decent move is at least alright for black, but I'll go into one fairly common line which has seen a bit of high-level play and is pretty good for black and as such the BDG player should be aware of it. After 4. ... e3 5. Bxe3 (Diagram 6) you might think that your position looks pretty good as you haven't sacrificed a pawn and you've developed another piece. Well, e3 is a mediocre square for your bishop, and your kingside knight cannot develop to its optimum square f3 now, so you're a little cramped and have possibly wasted a bishop move. From here white should just play good opening moves like Bd3, and maybe Nge2 with a kingside castle.
Diagram 6: After 5. Bxe3
+---+---+---+---+---+---+---+---+
|BR |BN |BB |BQ |BK |BB | |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP |BP | |BP |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | | | | |BN | | | 6
+---+---+---+---+---+---+---+---+
| | | | | | | | | 5
+---+---+---+---+---+---+---+---+
| | | |WP | | | | | 4
+---+---+---+---+---+---+---+---+
| | |WN | |WB |WP | | | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | | |WP |WP | 2
+---+---+---+---+---+---+---+---+
|WR | | |WQ |WK |WB |WN |WR | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
- Caro-Kann: 1. e4 c6 2. d4 d5 3. Nc3 dxe5 4. Bc4!
It has been remarked that the Caro-Kann Defense is a chess puzzle with white to move and win. Even so, it's remarkably dull and sleepy and who wants to play like that anyway? Tricking the Caro-Kann player into a BDG is a good way to spice up the game dramatically. In Diagram 7 rather than the expected 4. Nxe4, we have surprised them with Bc4 (pre-empting the problematic e5! if we had played f3 directly) we have a completely different game than black was hoping for with their tedious defense. Black will typically reply with Nf6 or Bf5, which you follow up with f3!, leading into back into fairly mainline BDG territory. Enjoy this nice break from the boring Caro-Kann.
Diagram 7: After 4. Bc4
+---+---+---+---+---+---+---+---+
|BR |BN |BB |BQ |BK |BB |BN |BR | 8
+---+---+---+---+---+---+---+---+
|BP |BP | | |BP |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| | |BP | | | | | | 6
+---+---+---+---+---+---+---+---+
| | | | | | | | | 5
+---+---+---+---+---+---+---+---+
| | |WB |WP |BP | | | | 4
+---+---+---+---+---+---+---+---+
| | |WN | | | | | | 3
+---+---+---+---+---+---+---+---+
|WP |WP |WP | | |WP |WP |WP | 2
+---+---+---+---+---+---+---+---+
|WR | |WB |WQ |WK | |WN |WR | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
Summary
While the BDG is hardly the most solid or exciting gambit around, it is a nice surprise to have on the repertoire. It also can transpose quite easily into the much more interesting Diemer-Duhm Gambit, so that's also an added benefit.
It also has an inordinately large cult following, and many books and even periodicals have been written specifically about this opening. I imagine this is because it's intended to be primarily a d4 opening, and d4 tends to lead to quiet openings, so even a somewhat dubious gambit beats the stuff you'd be used to seeing with a QGD.
Resources:
Chessbase 8 use to cull game statistics.