What's Vasik Rajlich doing today?

[Graham Banks]

Fabien created Fruit, Vas copied Fruit....has the little light bulb gone off yet

The programmers can't agree over the Fruit/Rybka issue, so how would I know what the truth is?
Try to have some manners for a change.

[Rebel]

Not sure what this has got to do with the issue of whether rule #2 is about copyrights. And it seems to me that in either case it is not the number of differences that is relevant, but how much was similar.

Did you read? Nothing is similar.

Every major evaluation ingredient is coded differently, mobility, king safety, passed pawns, double pawns, backward pawns, Rybka is missing Fruit's late endgame knowledge, Rybka has a material table – different from Fruit. Rybka does not contain Fruit's quad function, Rybka’s trapped bishop evaluation is different, rook evaluation is different, bishop pair evaluation different and most importantly, Fruit evaluates in stages in a unique way whereas Rybka adds directly to its score (as every other program on the planet does).

You never looked at the evidence.

Even the most simple evaluation of all (the double pawn) is evaluated differently. Fruit has a fixed penalty value for the mid and endgame. Rybka only evaluates for the endgame. Just to give you an example.

[Frank Quisinsky]

Hi Graham,

read not only what you want to read. The thread , the forum is full of information which reflects a different opinion than yours. You should try to respect it.

Best
Frank

[Frank Quisinsky]

Hi Bob,

a good response to dubious prevent repetitions. Today I think the only that is important. More can`t do a community. Only those directly involved can provide a very detailed explanation.

Best
Frank

[Graham Banks]

Hi Graham,

read not only what you want to read. The thread , the forum is full of information which reflects a different opinion than yours. You should try to respect it.

Best
Frank

I could post the same message to you, Frank.

I am not a programmer.
If programmers disagree over the issue, then you should respect the fact that non-programmers like me cannot possibly know which group of programmers is right and which group isn't.

Regardless of this, what really upset me was the way that Vas and his family were treated like shit.

[Rebel]

It's what I said all along, if you can't proof a derivative work then what the verdict was about is the usuage of "too many" ideas.

And even that is wrong.

Every major evaluation ingredient is coded differently, mobility, king safety, passed pawns, double pawns, backward pawns, Rybka is missing Fruit's late endgame knowledge, Rybka has a material table – different from Fruit. Rybka does not contain Fruit's quad function, Rybka’s trapped bishop evaluation is different, rook evaluation is different, bishop pair evaluation different and most importantly, Fruit evaluates in stages in a unique way whereas Rybka adds directly to its score (as every other program on the planet does).

Other key differences between Fruit and Rybka:

1.Time control is different
2.Fen parsing is different
3.Rybka extracts the mainline from the transposition table (TT), Fruit via the classic triangle table
4.Rybka 1.0 beta displays a mainline of maximum of 10 moves, Fruit produces much longer variations
5.Rybka uses a bitboard board representation whereas Fruit is mailbox
6.Rybka’s pawn value is 3200 (which is unique), Fruit uses the classic value of 100
7.The order in the evaluations of Fruit and Rybka are not similar
8.Rybka has lazy evaluation, which is absent in Fruit
9.Futility pruning is different between the two programs
10.Rybka uses Late Move Reductions (LMR) whereas Fruit uses history reductions
11.Fruit uses a history table which is absent Rybka.
12.Fruit only has one evaluation table (king safety) while Rybka has many
13.The two programs have a different move format
14.Rybka does not handle promotions to minor pieces
15.The two programs have different hash table code
16.They have different handling of repetitions and the 50-move rule in search
17.Fruit maintains piece-lists which are not present in Rybka
18.Fruit maintains a pseudo "bitboard" for pawns, Rybka has the real thing.
19.Contrary to Fruit, Rybka needs to update 4 rotations of occupancy bitboard
20.Contrary to Fruit, Rybka updates a rough estimate of material balance with weights of 1:3:3:5:10 (in the evaluation this value is then corrected by a delta obtained from the material table)
21.Fruit has a 16*16 square mailbox, Rybka has an 8*8
22.The programs have different Zobrist hash keys
23.The programs have different user interface options

We found 35 indisputable differences (some of which are very fundamental), not counting the ones that are debatable such as the Piece Square Tables (PSTs) and the contents of the TT.

Doesn't fit the definition of a derivative work.

Differences do not matter, it is the similarities and the number of them that violate rule 2. 75% of what you cite above comes from the mailbox/bitboard differences. Irrelevant in this context.

Nice try, no cigar.

All the evaluation elements were removed from their data structure, either mailbox or bitbaord. Every evaluation ingrediënt is coded differently, thus NO SIMILARITY.

What's left for you was to find traces of clear code copying. And as you admitted you did a lousy job. No surprise, because it wasn't there.

Double strike.

[Frank Quisinsky]

Hi Graham,

what have the family to do with it?

Fabian have a family too.
Please not forget the familys of honestly programmers.

Very one-side your opinion! Perhaps because CCRL testing this whole clone stuff. Different commercials must be very happy with CCRL. Very angry, but the impression is created after all public information to that topic in combination with your latest comments.

However, I must admit that the decision what is to test and what isn`t designed to be difficult. I am sure not possible today to find the 100% right way.

But I call for honesty or referred to in respect to copyrights!

Best
Frank

[Sedat Canbaz]

Hi Graham,

read not only what you want to read. The thread , the forum is full of information which reflects a different opinion than yours. You should try to respect it.

Best
Frank

I could post the same message to you, Frank.

I am not a programmer.
If programmers disagree over the issue, then you should respect the fact that non-programmers like me cannot possibly know which group of programmers is right and which group isn't.

Regardless of this, what really upset me was the way that Vas and his family were treated like shit.

Another BIG upset is that,
According to Simtool (some of those who signed this letter against Vas) They studied (or copied) 'too much' from Ippolit (Rybka)

And if Rybka is a clone:
That means their engines (who used Ippolit's ideas) are not original too

Just saying

Best,
Sedat

[Frank Quisinsky]

Hi Sedat,

Please do not speak always of Rybka. Please talk about Rybka 1. What is a causal chain? Easy to learn if you look into the past, must not be a computer chess topic.

Best
Frank

[Sedat Canbaz]

Hi Sedat,

Please do not speak always of Rybka. Please talk about Rybka 1. What is a causal chain? Easy to learn if you look into the past, must not be a computer chess topic.

Best
Frank

Hello Frank,

The answer of your question is on my previous posting

Hopes helps...

Best,
Sedat