What makes the DDG interesting is that a number of serious openings can transpose to it, like the Nimzo-Indian Defence 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. f3 d5 5. e4, and the QGD Tarrasch Defence, Marshall Gambit 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. e4 dxe4 6. d5. In addition to Marshall, also Janowski, Grob and Bronstein occasionally played the latter variation.
Ideas can also be found from a bunch of other Diemer gambits where White sacrifices the e4-pawn, and plays f3: Alapin-Diemer 1. e4 e6 2. d4 d5 3. Be3 dxe4 4. f3, Dutch-Diemer 1. d4 f5 2. e4 fxe4 3. Nc3 Nf6 4. f3, and the nearest relative Blackmar-Diemer (BDG) 1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3. In other words, a good DDG player -- if there can be such a creature -- has to know theory of diverse openings. But instead of memorizing long variations, he should rather understand the underlying motives.
The DDG looks like an inferior variation of the BDG. The main excuse I can think of keeping playing it is that they have already published several books on the BDG. It is unlikely that anyone would bother to write one on the DDG. Well, maybe I might some day...
I had been maintaining the DDG pages on the Web for almost two years when Tomas Segerberg from Sweden suggested in summer 1996 that we would organize a thematic DDG e-mail tournament. Of course, the main reason was to find how easily the DDG can be busted in CC games. In blitz, the DDG had been very successful.
In October 1996, the first DDG Accepted e-mail tournament was started with 34 participants, and 100 scheduled games. Everyone could play any even number of games up to 10, so this was no serious competition: no clear rule for deciding the winner, and no prizes.
CC games take time, and we had quite standard reflection time: 30 days for 10 moves. Yet one player withdrew from the tournament saying he was tired of waiting opponents' moves -- and this happened when the tournament had been running for five weeks!
How could we possibly avoid the computer problem in an e-mail tournament where all moves are transferred via computers. Fortunately, we have had only one case so far where two players were suspecting each other of using a chess-playing program.
I have used Genius 2 in post-mortem, and it sure is fun to see how long it sometimes takes for a program to realize what is going on. Anyway, I am sure that if you let a program like Genius 2 (rating over 2350) analyse a game overnight, it definitely will find a better move than any non-master player. But why spoil the pleasure of finding moves by yourself?
What is the idea of playing CC games if known theory lines are followed up to move 25? When 3. c4 is played in the French Defence, most players are out of the book immediately; even in the DDG tournament, everyone is out of the "book" by move 10 at the latest. In unclear positions, imagination is the primary weapon. I would not like chess only as a theoretical study.
I claim that players learn more in offbeat tournaments than in ordinary ones. They have to plan the game from the very beginning; simply, they have to think more. Of course, few can find improvements to established openings, but like a bad plan is better than no plan, similarly a bad -- well, original -- thinking is better than no thinking. When one thinks, he may understand.
If I had spent all the time with serious openings, I probably would be a better player by now. On the other hand, trying to keep up-to-date knowledge of some common opening is quite hopeless. It is impossible to comprehend tens or hundreds new games every week; even GMs have seconds who help to go through the latest databases. Hence, playing a rare opening is both lazy and effective: you can easily be one of the few experts in the world.
Thematic tournaments are excellent for collecting new ideas on openings. The DDG is unique in that those who play it almost never will meet it as Black, so it is very instructive to play it on the other side for a change. Moreover, one can sometimes utilize his opponent's ideas in other games. For example, after 4. Nc3 Nf6 5. f3 Bb4 6. Be3 Nc6, I met an attractive move 7. Qc2, which I had somehow overlooked before. It looked so impressive that I played it instantly in another game (via transposition, though; see Heikkinen - Watson below) -- and managed to knock-out my opponent.
After 4. Nc3 Nf6 and 4... Bb4, players with the Elo rating over 2000 preferred playing 5. Nge2. White plays f3 in all other Diemer gambits, so one might "require" that f3 should be played in order to call the gambit the DDG.
Why would anyone play the DDG in the first place if he does not want to play f3? Some players probably like the king's knight on e2 because it gives the best chances for White to equalize: to struggle a positional game, and even sometimes win the pawn back. To me, however, the whole point is to search for sharp attacks. In other words, an exciting tactical game -- whatever the result -- gives me more pleasure than a dry positional win.
I took the tournament seriously: it would have been embarrassing to lose all my games as White. Having won all my four games as White, I must admit that I was more than happy. Stewart Sutton wrote me when he resigned: "You have upheld the honor of your gambit."
I learned that it is easy to underestimate White's attack even in e-mail games; I had terrible positions only as Black. On the other hand, White has not done too well as a whole, scoring only 40 % so far (after five months, 3/4 of the games being finished). A few players even wrote me that they lost faith in the DDG during the tournament.
One for all, and all for 1-0. It is most challenging to play an opening in which you have to find the moves, and in fact, the whole plan, by yourself. One really has to study, try to understand, the ideas of the opening. By playing the Ruy Lopez, for example, you could easily avoid creative thinking in the opening, and perhaps even go to endgame just by following well-known lines. I do not think that copying moves is the best way to understand chess.
The DDG pages on the Web contain hundreds of games, detailed
analysis and various texts:
<http://www.funet.fi/pub/doc/games/chess/ddg/>