comments on the amy/yace book on Morgans site

[Aaron]

Geschrieben von: / Posted by: Aaron at 03 July 2000 16:24:19:
Okay, please understand that I'm no opening expert..I'm in fact a very weak player, but I decided to try out the book to see if there were any huge gaps in the opening book.
Recently, I was surprised to see Yace totally misplay a Evans Gambit, because it's book ended after 7 moves..
Hence this idea to test..
Due to the nature of the opening books made from games, some opening lines are under-represented, so I ran a few quick games using the various openings/lines to see if there were a few lines missing..
The idea of course, is to ensure that the book covers the most basic lines, that even a weak player like myself "knows"..
I'm not going to critise the choice /strenght/weakness of book opening lines (I;m too weak to do so), just point out areas where the book is totally non-existent and should be there..

Trends for Amy book
1)As White

The book tends to play 1 d4 more than 1 e4 .
2)As Black
a)Against 1 e4
it "almost always" plays 1...e5 and if 2 Nf3 plays petroff 2..nf6
Sometimes though, it plays the sicilian defence (only against computers?)
b) Against 1 d4
It plays the Nimzo-indian defence usually..

Here's some lines I think that need beafing up

Amy is Black
A)1 e4 e5 2 Nf3 Nf6 3 Bc4 Nc6 4 d4 exd4 5 0-0 . Here the books ends
Amy now seems to like 5..Nxe4 or Bc5 both good moves but usually plays wrong after that...eg
5...Nxe4 6 Re1 f5?!
I admit, I sort of tricked the engine into this line, since usually with the petroff as it's main line, it doesn't need to handle this tricky variation..

The other 2 areas are non-critical but involve the King's Gambit..
1 e4 e5 2 f4 exf4 3 Nf3 g5 4 d4 and Black is out of book
Looks too early to be out of book..My 4 d4 is perfectly normal ( only 4 h4 is in the book now )
1 e4 e5 2 f4 exf4 3 Nf3 Ne7?!
This is another line that Amy favours against the King's Gambit..3..Ne7 might be a book move..But it's extremly rare..And I distrust such a move..
Why not add games, where Black played 3..d5

So, despite what I said about not commenting about strengths and weakness...
I still did..
I'll continue looking, but the books looks quite good as a whole..
A stronger player might see some weak lines..

One irriating thing is that as white, if allowed it prefers the scotch game rather than Ruy Lopez or 3 Bc4..
Nothing wrong..Here as well..Just my tastes..

[Mogens Larsen]

Geschrieben von: / Posted by: Mogens Larsen at 03 July 2000 17:13:44:
Als Antwort auf: / As an answer to: comments on the amy/yace book on Morgans site geschrieben von: / posted by: Aaron at 03 July 2000 16:24:19:

Trends for Amy book
1)As White

The book tends to play 1 d4 more than 1 e4 .
2)As Black
a)Against 1 e4
it "almost always" plays 1...e5 and if 2 Nf3 plays petroff 2..nf6
Sometimes though, it plays the sicilian defence (only against computers?)
b) Against 1 d4
It plays the Nimzo-indian defence usually..
Here's some lines I think that need beafing up

Amy is Black
A)1 e4 e5 2 Nf3 Nf6 3 Bc4 Nc6 4 d4 exd4 5 0-0 . Here the books ends
Amy now seems to like 5..Nxe4 or Bc5 both good moves but usually plays wrong after that...eg
5...Nxe4 6 Re1 f5?!
I admit, I sort of tricked the engine into this line, since usually with the petroff as it's main line, it doesn't need to handle this tricky variation..

The other 2 areas are non-critical but involve the King's Gambit..
1 e4 e5 2 f4 exf4 3 Nf3 g5 4 d4 and Black is out of book
Looks too early to be out of book..My 4 d4 is perfectly normal ( only 4 h4 is in the book now )
1 e4 e5 2 f4 exf4 3 Nf3 Ne7?!
This is another line that Amy favours against the King's Gambit..3..Ne7 might be a book move..But it's extremly rare..And I distrust such a move..
Why not add games, where Black played 3..d5
So, despite what I said about not commenting about strengths and weakness...
I still did..
I'll continue looking, but the books looks quite good as a whole..
A stronger player might see some weak lines..
One irriating thing is that as white, if allowed it prefers the scotch game rather than Ruy Lopez or 3 Bc4..

Most of the choices Amy makes is due to the Learn.db, which I created to even some of the book probabilities. Otherwise it would play 1.d4 every single time and respond with the sicilian to 1.e4 every time. It still needs some tweaking, but I'll wait until the new book has been made.
Your suggestions are noted and hopefully the added games will patch some of the holes. I've written down your comments and I'll check myself to see if it's only a learn.db problem.
The same as the Petroff. My fault entirely ).
Best wishes...
Mogens

[Gábor Szõts]

Geschrieben von: / Posted by: Gábor Szõts at 04 July 2000 08:44:07:
Als Antwort auf: / As an answer to: comments on the amy/yace book on Morgans site geschrieben von: / posted by: Aaron at 03 July 2000 16:24:19:

[Mogens Larsen]

Geschrieben von: / Posted by: Mogens Larsen at 04 July 2000 11:32:06:
Als Antwort auf: / As an answer to: Mogens is the chap's name. (no text) geschrieben von: / posted by: Gábor Szõts at 04 July 2000 08:44:07:

[Aaron]

Geschrieben von: / Posted by: Aaron at 04 July 2000 18:46:50:
Als Antwort auf: / As an answer to: Re: comments on the amy/yace book on Morgans site geschrieben von: / posted by: Mogens Larsen at 03 July 2000 17:13:44:
Okay so I downloaded the 4 large.zip files from Crafty's site. Combined then with 2600.pgn to get a gigantic 112 Mb file..
I played around using different ply, finally settled on
Book_create 100000 26
The final result is a big 21 Mb opening book. I doubt I can make it much smaller..
It so far looks okay..Like the Crafty books that I have it plays Ruy lopez primarly..and defends when possible the black side of ruy lopez..
The side effect is that Yace ver Crafty matches becomes endless rounds of ruy lopez..
Playing a few g/5 games, it seems that Yace is outplaying Crafty at Ruy lopez once leaving book on the white side..Which is good..
Except for a ocasional Evans Gambit..(It plays 7 0-0 now..altough it is out of book soon)
Still Crafty seems to have a bigger book, since it tends to stay in book longer..
Concluson: Other than the size of the book, i'm quite satisified with the result..Also, I might consider marking the pgn book to ensure that Yace responds with the Sicilian against 1 e4 , or french or whatever, rather than try to defend the black side of the ruy lopez..