Fabien's open letter to the community

[geots]

I am lost in this avalanche of post so I must ask someone to enlighten me: if all Fabien saw was his own code and the Strelka code, how is he to know what was the way Rybka was made? He has only the same two source codes at his disposal which have been there for studying for more than 3 years.
So what is new here that makes some posters think Rybka is illegal?

I would imagine much to Bob's dismay, Rybka is here to stay. All I see is an interesting direction to an old worn out argument

[geots]

Yea, jealously never ceases to amaze me. This subject is about as old as Noah's Ark: there was an arc, there wasn't. People still bitch while Vas keeps going to the bank.

[geots]

Help me here. Who was that little midget that started all the lunacy with Christophe

[Dr.Wael Deeb]

I am lost in this avalanche of post so I must ask someone to enlighten me: if all Fabien saw was his own code and the Strelka code, how is he to know what was the way Rybka was made? He has only the same two source codes at his disposal which have been there for studying for more than 3 years.
So what is new here that makes some posters think Rybka is illegal?

I would imagine much to Bob's dismay, Rybka is here to stay. All I see is an interesting direction to an old worn out argument

Of course Rybka is here to stay....but unfortunately it's current staying is dancing between 2nd & 3rd place in the rating lists nowadays

Of course we're talking about the rating lists....

[geots]

Help me here. Who was that little midget that started all the lunacy with Christophe

[tmokonen]

I wonder if, after all of the forum verbiage over the years, someone actually bothered to get a hold of the FSF people.

[bob]

Students are quite good at this kind of obfuscation. One can do the above to improve speed (one popcnt vs N BSF instructions in a loop) or to make the code appear to be different (both do the same thing, but look significantly different, particularly if you change the variable names as well...

You are very strong teacher. I would not want to be your student.

Another example. In the function SEE of Ivanhoe, we can find the following:

Code: Select all

  do
    {
      cbf &= ~bit;
      mask = BitboardOppP & bit;
      if (mask)
	{
	  bit ^= (~(mask - 1)) & mask;
	  PieceValue = ValueP;
	}
      else
...

Obviously, this is a mistake. After the capture by a pawn on the open diagonal can be an bishop or a queen. In Houdini this bug is corrected:

Code: Select all

  while (bit & OppOccupied) {
    if (mask = BitboardOppP & bit)
      {
        capture_value += 100;
        if &#40;capture_value < -60&#41; return 0;
        from = first_one&#40;mask&#41;;
        occ &= ClearBit&#91;from&#93;;
        bit &= ClearBit&#91;from&#93;;
        bit |= BMagicAttacks&#91;BishopIndex&#40;to, occ&#41;&#93; & diag & occ;
      &#125;
    else
...

Is it also plagiarism?

Hard to say. That is a pretty small piece of code. And there are not a lot of ways to deal with pawns, except to remember to fill in a bishop/queen that is diagonally behind the pawn in the right direction.

I'm sure there have been cases of students copying programs, and then correcting bugs along the way.,

Does make it harder to detect, particularly if that was the only code copied.

As far as being my student goes, they simply know they had better write their own code, and they do. And that is the goal...

[bob]

Bob, a big difference between 1995 and now is that now you can encrypt, zip and email the source to yourself and it will take you 3 minutes. It is that simple.

Why was that so hard in 1995? We had LANs, and from home WANs or at worst 56kb modems. Encryption/zip has been available forever on unix / linux...

I read long time ago when Strelka came out someone asked Vasik whether it might be possible that his code got stolen, he said no, because he keeps it a dedicated computer with no internet connection.

A person who takes such precautions would surely take a minute or two to take care he has a backup copy.

[bob]

I don't use free email machines. Non-secure and I have too many discussions about student grades and such. My email is on my office box for the same security reasons. The US FERPA (Family Educational Right to Privacy Act) is pretty onerous and requires reasonable protection for student discussions. gmail, yahoo, etc do not provide that.

OMG. I hope you've heard of IMAP????

I have also seen where those public machines have been broken into, and files copied (including 100Ks of credit card numbers). IMAP won't help you one bit there...

[bob]

Send it to a friend or a family member.

Which would mean "quantity over quality?"

10 highly unreliable friends are much more reliable overall than 3 highly reliable storages...
Basic statistics. Say probability for each of your friends to lose your emails is 10% and probability that one of your reliable storage fails is 0.1%.
Overall it's 0.1^10 = 1e-10 vs. 0.001^3=1e-9 .

I'd suspect that probability is more like 95% for friends losing a backup email message, storage is not free and we are talking a meg or two for each copy...

Suddenly it doesn't look so rosey...