What well known gambits are unsound?

I don't think albinn counter gambit is unsound, but dubious at least. Evans gambit is sound but nothing special if black know what he's doing. Englund gambit is probably unsound, not so sure about elephant gambit. Black can get an advantage from the king's gambit i think if he knows what he's doing, so depends what you consider unsound I guess. I find it hard to believe that haloween gambit or traxler gambits are sound.

All sidelines of the Englund are refuted (2...d6, 2...f6, etc., although i play all nearly all of them with good success OTB and in corr.Chess), but the Standard Englund seems to be unclear, maybe +=. The theory material is rare...

Elephant is += according to the latest books about this opening, but it offers good practical chances.

Yeah maybe Englund is dubius, and same with traxler, certainly I wouldn't be well prepared to face the traxler OTB but with a computer you can probably find it isn't the most promising choice for black but white has to play accurately

Most of these unusual gambits are probably sound but just not the best, the Budapest gambit also.

Only the most common gambits are theoretically "sound", like the Wolga-Benko-Gambit or the Blackmar-Diemer.

But the point is, that most amateur players dont know the good lines of refutation, because they rarely face this gambit in a match.

I also wouldnt spend much time of learning the theory of rare gambits. Even if you would learn them, you would not memorize many move orders, if you dont play them alot.

My guess is the Blackmar-Diemer Gambit is unsound.

I'm not sure if the Blackmar-Diemer has been specifically refuted, but that doesn't make it any less terrible

Vince, do you mean you never lost a game playing the Blackmar or that you never lost a game defending the Blackmar?

I will guess when that gambit arose after 1. e4  d5  2. d4  you, as Black played a declined variation vs the Blackmar-Diemer?

Gambits are only unsound if your opponent knows how to refute them. The truly unsound gambits don't show up in GM games. Favorite gambits of mine are the King's Gambit and Budapest Gambit (the last may not be sound but I don't know the refutation and so keep playing it)

Is this in opening books?

Yes the line 1. e4  e5  2. Nf3  d5 is called the Elephant Gambit and while it is probably unsound--it is playable and hard to refute.

The Budapest has a trap that leads to mate in six or seven moves if White is playing carelessly on the move before mate; the moves leading up to it appear pretty reasonable

Never saw a convincing analysis for this assertion...

But even it would be unsound, i would play it.

my statistics with the BDG

Correspondence chess: 31 wins, 4 losses, 4 draws

OTB: 14 wins, 2 losses, 3 draws

That is great that you can play that gambit and get such good results!

and yes you should play it until you happen upon a line that refutes it.

But if you ever get your rating a lot higher then consider dropping it.

Not sure about Blackmar-Diemer, probably sound, but only just. Also Vincent_Valentine if black can get equality then it is good for black not white, as white has an opening advantage from the start, however I think white can achieve an advantage from the Budapest.

Well if white plays well then white is going to have an advantage. You're saying black shouldn't "settle" for equality but how is black going to get more if white plays well, as I say they shouldn't even get equality.

Thanks, David...but i only play chess for fun, in club and online, not for ratings...so when i play the Latvian Gambit and my opponent knows some kind of refutation, its OK for me to lose, but even to win a +- position you need good technical skills...so you can win a match out of a theoretical lost position. Dont forget...most of us are amateurs!

When i lose a match with the latvian or the BDG, i will start a new one

:-)

Best Regards

Marcus

Looks like we got ourselves a new gambitking ere

Thanks alot...if i would play that stuff, that you prefer (moving pieces around the board), i would die of boredom or i would quit chess...