Thank the lord that most people do not carry around opening books on how to defend against an opening :).
With the argumentation some are using most openings should be completely forgotten for black.
No one is saying the Latvian is sound. But it's a nice surprise weapon.
No. It's junk. Learn chess, not tricks.
The question is not whether it is unsound, but rather, how unsound is it?
I had to stop playing the Latvian because it was insufficiently unsound. Now I often play the Elephant Gambit 1.e4 e5 2.Nf3 d5 and I win more than half my games with it.
In Live Chess, it's not really that important to debate whether an opening is unsound. Very few people know these unusual openings enough to refute them over the board. In 5 minutes or less, Black's superior knowledge of the opening more than compensates for any deficiency in the opening.
To prove the point, I've been playing 1.e4 f5 2.exf5 Kf7 as Black and enjoying great results with it in 3 min and 1 min.
Risky openings are certainly fun to play. But the Latvian is 100% unfounded, positionally, and white can have a very good game without carrying any book- just by playing regular, sane developing moves. For example, try to bust that one:
1.e4 e5 2.Nf3 f5 3.Be2!?
Now 3...fe4 4.Nxe5 is a reversed KG, 3...Nc6 4.d4 a reversed Vienna, 3...Nf6 4.ef5 not any better than the above, and so it goes. White's innocuous third move is a very handy tempo won over well-known positions in reverse, and Black will be hard pressed to equalize.
BTW I have not found any games registered after 3.Be2, so it maybe is fun to try it - playing white, that is!
The wheel was invented several thousand years ago, no need to reinvent it. The Latvian was invented at the romantic age of chess, and was fun- but today, even a relatively weak chess engine will burst your ...f5 bubble with no trouble at all.
pfren, I have a couple of comments for you.
cigoL, coincidentally, my little Blackberry chess program plays Be2 against me. It always follows the same line:
1.e4 e5 2.Nf6 f5 3.Nxe5 Nc6 4.Nxc6 dxc6 5.Be2 Qh4 6.Nc3 fxe4 7.O-O and I proceed to bash my head like a seige ram against the castle walls for the rest of the game.
You're playing someone in a tournament. The game goes 1. e4 e5 2.Nf3 f5?! You stare perflexed at this phenomenal move. You cautiously analyze each option you have. Is this necessary? This is the question I have for you. Several people have suggested f5 as a dubious move. Being a Latvian gambit player myself, I tend to question this move. According to game explorer, 2... f5 wins more games than 2... Nc6 does for black. Only you can decide for yourself. To assist you are two games I found using the Latvian. I intend to settle this debate for once and for all.
P.S. And whether or not I should use the Latvian Gambit.
I think the Latvian Gambit is favorable for Black because in most cases it will put White on the defensive, break White's concentration and tempo allowing Black to gain the momentum.
You're playing someone in a tournament. The game goes 1. e4 e5 2.Nf3 f5?! You stare perflexed at this phenomenal move. You cautiously analyze each option you have. Is this necessary? This is the question I have for you. Several people have suggested f5 as a dubious move. Being a Latvian gambit player myself, I tend to question this move. According to game explorer, 2... f5 wins more games than 2... Nc6 does for black. Only you can decide for yourself. To assist you are two games I found using the Latvian. I intend to settle this debate for once and for all.
P.S. And whether or not I should use the Latvian Gambit.
Here's a way to find out empirically: Latvian Gambit Tournament. 
Let's put this thing to the test!
Hi melvin..., join the tournament, and try it out!
pfren, you should join the tournament too, to put the Latvian Gambit to shame, not just in words, but in play.
There's a difference between an opening being sound and an opening being playable.
To me, "sound" means that with optimal play on both sides the person choosing the line gets what they want. For black in a gambit line that means that they need to achieve dynamic equality, where htey have full compensation for the pawn. I don't believe this is posible in the Latvian.
To be "playable" means that you can get exceptable results using that opening that won't be worse than what you'd expect playing any other opening correctly at that player's rating.
The Latvian is definitely playable. In a practical game the surprise value and lack of knowledge the average opponent will posses makes it rather formidable. But it's almost certainly not sound.
But below GM level, who cares if it's sound. Isn't the point to have fun?
We may need to define what is meant by the word sound. The lower the grading of the opponent the more sound will become what would be unplayable against an expert player. The latest computer technology has thrown some so called sound sacrifices into question.
I suggest the following new definition of 'sound'.
A move can be said to be sound if it produces an advantage under the circumstances in which it is played.
I know this is wide open, but it is at least a sound definition and will enable all the arguments to be settled.
Those who wish to debate further could of course then take up the cudgle on sound sound moves or unsound sound moves.
gee, I dunno phren. I admit that white does have a better continuation from that line than Morgado-Elburg 1978 0-1. Maybe you are on to something, but for now the Frayzh still looks good to me.
I've read that the Latvian Gambit is actually more successful in correspondence games, than OTB games. If this is true, it can't be so horrible. The game I posted earlier was a correspondence game too.
At the GM level, the Latvian has scored 25% in correspondence games, and 33.3% in OTB games at classical time controls, so I think actually it's the other way around. Might do better in blitz though.
Where did you get those numbers, riga...? I read it in a book on the Latvian Gambit.
I keep a database of GM games for both correspondence and OTB. The only black win is Apicella-Ivan Sokolov, European Team Chamionships 1992. Other than that it's mostly white wins.
Nice! How many games in the database in total? How many games in the database with the Latvian Gambit?
The Latvian Gambit is ultra risky it's anything but safe the Latvian Gambit is the equiviliant of holding a big red stick of dynamite that may blow up in the white players face or the black players face.
It's not for everyone if black likes to play very cautiously and safe doesn't like wild tactics chaos or gambling danger doesn't have the nerve to dance on the edge of a straight razor with a lit stick of dynamite the Latvian isn't for him or her.
After having played it OTB I concluded it it was more like gathering up a huge charge of static electricity and grabbing someone's arm; usually shocking(literally and figuratively) for the other guy, and can be very amusing... provided, of course, that you can stand the charge of electricity shooting through your arm in the first place.