A lot of its adherents, mostly lower rated players, swear by it. On one website one 1400-rated player went so far as to say that IM Jeremy Silman did not know what he was talking about when he wrote, “...the fact that no grandmasters use it speaks volumes for its true lack of soundness."
The fellow pointed out that Spassky once won a game with it and Fischer once lost to it. I'm not sure what game Spassky won, but Fischer's loss was to Viktor Pupols in the 1955 US Junior Championship...which proves nothing. See the game HERE.
He also pointed out that IM Tony Kosten wrote a book on the Latvian Gambit. First of all, Kosten's book was written in 1995 and I'm sure it has a lot of tactical errors that today's engines would spot instantly. Secondly, we also know that when an author publishes a book in which he recommends a dubious or obscure opening he is going to select less than stellar games for examples to “prove” his point. He usually has to because there isn't likely to be a lot of GM games available.
As one player wrote of his experience playing the Latvian Gambit, “Chances of my playing it again: I'd rather beat myself around the head with a brick.” Read article...
I play it sometimes in online games; sometimes it works, sometimes it doesn't. As I mention in the game notes, I don't know any book lines on this defense. I really don't need to because when I looked over some of my games with it the average point where my opponent made a non-book move was move 5. So there's little point in trying to memorize anything. Here's another little surprise: I checked the last 10 online games where I played the Sicilian and the average point where we left the book was move 5 or 6! So much for the belief that we lower rated players need to memorize a ton of variations.
Taming Wild Chess Openings by John Watson and Eric Schiller is an interesting book that tells you how to “deal with the good, the bad and the ugly.” Good openings are, of course, just that...good for tournament play. Bad openings are described as fun, but ultimately lead to a significant disadvantage against best play. Ugly openings are played in tournaments fairly often and aren’t necessarily bad, but they usually violate some basic opening principles and look wrong at first sight even to inexperienced players. I like they way they have cute little icons that further refines the variations in the book:
Monkey - can be used just for fun but it is not recommended for important games. They tend to be offbeat and will lead to original and entertaining situations
Thumbs down – cannot be used successfully in serious games.
Poison – will seriously damage your position and is considered toxic. Don’t play it
Rabbit - good for playing against lower rated competition...”rabbit-bashing.”
Snake - can bite you if you are not properly prepared.
Check Mark - sound but perhaps difficult to play well.
The Latvian is an “ugly” opening. If you want to know where your favorite opening stands in their classification you can check it out HERE.