But the Avrukh book is apparently a great book, so I don't know why you would play the London.
1.d4 repertoire advice.

Because it would take years to go through all the lines?
But no, it's still not worth it to take years sucking at chess by playing the London.

the queen's gambit is not a true gambit whether accepted or declined. Only play 3. Bg5 if 2. ... Nf6

1 error in a 450 page book, WHOAAAAAAAAAAAAA.
I've had that book recommended to me by GM's, it can't be that bad. You should just check the lines you are playing before you play them.
And if you can find one book that doesn't have an error (or lots of errors), I will be impressed.

Avrukh's book is very good, and I don't really care what engine boys say about it. The basis of his repertoire is sound, and an occasional mistake has absolutely no value for class players, or for educational purposes. Chess professionals wouldn't worry either, as they always check the served food themselves.
All that sais, Avrukh's books may be very good, but they are quite useless for class players.

Agreed, Pfren! Avrukh's books have won awards by people who play chess professionally. Sure, there may be a few errors, but the books are treasure troves of great ideas.
My main problem with Avrukh's repertoire is that it's not particularly good for correspondence chess because the critical lines are not only just very slightly better for White, they don't offer Black enough opportunities to go wrong. But that qualm is only in regards to correspondence chess.
Avrukh's ideas have repeatedly been seen in GM games since his books came out. That's not a coincidence.

Well, it's the players job to test the lines that a book recommends, or at least research them. If a class player decides to play a recommendation in a book without checking it, and suffers an Anand style 6 move loss, it's as much the player's fault as the book's. And I doubt any of Avrukh's lines are that bad.

Which game was it then. You give no evidence, only say that one unimportant game in a two volume set of huge chess books that has advanced theory far passed what you ever could is bad, and yet argue against a book that many grandmasters would recommend.
I think the odds are against you my friend.

it is not the only example, but the most glaring, flagrant, egregious instance -- as I mentioned -- is to be found in the C21 Catalan line he recommends on page 120 of volume 1.
Shamash also said it was on page 190 but he has changed what he has said and mentioned this position on page 120 now where Avrukh believes 19.Bf4!N to be an improvement.
For those who don't have access to the book i will post the diagrammed postion that Shamash is crying about with Avrukh's 19.Bf4 inserted and black to move:

it is not the only example, but the most glaring, flagrant, egregious instance -- as I mentioned -- is to be found in the C21 Catalan line he recommends on page 120 of volume 1.
Shamash also said it was on page 190 but he has changed what he has said and mentioned this position on page 120 now where Avrukh believes 19.Bf4!N to be an improvement.
For those who don't have access to the book i will post the diagrammed postion that Shamash is crying about with Avrukh's 19.Bf4 inserted and black to move:
Shamash is right, that line is good for black but I think black has an improvment before that point, which refutes the line (an h6 move somewhere I believe). One of the few inaccuracies in an otherwise great book though.
And as I said, players should check the lines before they play them. On bad line does not ruin a book.

Perhaps Shamash can explain and educate us mere mortals and give us some insight into his correspondence with Avrukh and exactly what variations cause this line to be completely winning for black...
I mean i followed the rest of the line in the book through and White sacs the exchange on d3 and manages to break up black's imposing pawns, for me it doesn't seem to be too be too tragic at all for white but i will never be a chess master so maybe Shamash can explain some wiining lines for black.

No, I also know for a fact that there is some point in that line (a6 against the catalan) where black can play h6 and lock the dark squared bishop out of play, securing a nice advantage. I'm pretty sure it's in a position before the one you posted, although I'm not sure that I remember the line exactly as I don't play this with either color.
Think that a $30 opening book is good enough to trust 100% for correspondence use is insanity.
In the history of chess, there hasn't been a single opening book that didn't have mistakes in it, and you're supposed to do your own work with them.

Shamash, you claimed that Schandorff's book on the Queen's Gambit is better. It's an excellent book, but it is much less detailed as a repertoire book and also has numerous little flaws. Pfren has suggested that the Queen's Gambit Exchange variation, which forms the backbone of Schandorff's book, does not give white an advantage in key lines that Schandorff doesn't even cover properly. I'm not sure about PFren's evaluation of the QGD Exchange, but he's right that Schandorff doesn't really deal with that key variation.
Again, Schandorff's book is also excellent, but I'd rather a book be wrong about a sideline that can be fixed than for it to be wrong about its main premise.
Jeremy Silman has an excellent book review which discusses the strengths of these two books. He agrees they are both fantastic. He says,
"[t]o call Avrukh conscientious would be an understatement. ... There is no question that Avrukh’s book features an unusual level of detail, and the claim by the publisher’s that it "will certainly be read by grandmasters” is right on the mark...
Silman's conclusion makes an important point:
"One last and very important point is to consider your playing strength when considering whether to buy either or both of these books. They are principally aimed at players over 2200 on up (no limit!). Players from 2000-2200 will definitely have their hand full whether it is trying to learn to play the many types of middle game positions that offer White small advantages that Avrukh recommends or the main line theory of Bg5 against the Semi-Slav or 5.a4 Bf5 6.Ne5 lines in the Slav advocated by Schandorff. Those below Expert level should concentrate on improving their overall game before taking on such demanding material. (Emphasis added.)
The entire review can be found here: http://www.jeremysilman.com/shop/pc/Playing-The-Queens-Gambit-p3542.htm

Funny you should mention #5 which is rife with errors and has led to the author and many players who follow the book being taken apart by friends of mine. GMs Shulman and Akobian have both found numerous issues with Vigorito's Play the Semi-Slav. Especially in his coverage of the Slav Exchange, his analysis is not so accurate.

I have another Vigorito book (on the Marshal) which is worth little more than pulp. At least Milos Pavlovic has many errors in his own Marshal book, but he has done some remarkable work and personal analysis.
Marin's books also have several errors, but they are hands down the best opening manuals out there. You just have to know HOW to read them.

pfren, what do you think about Sabino Brunello's book Attacking the Spanish? It's a bit dated now but it has some interesting analysis and ideas...

The most interesting part in Brunello's book was about the Gajewski, which unfortunately is borderline playable. The Jaenish part was just OK (Sokolov's stuff on the gambit is just superb), and the Marshal one below par (but still much better than the Vigorito book).
This is kind of my repertoire, though often im lazy and will place the London rather than QG lines:
1.d4 nf6 2.Bg5 =Trompowsky
1.d4 f5 2.Bg5 =Hopton
1.d4 d5 2.c4 =Refer to Avrukh 1.d4 volume 1
OR
1.d4 d5/e6 2.bf4 =London system, if you dont feel like learning Avrukhs libes.