About the code of strelka

[Vempele]

Little Fish
Little Arrow

See the similarity now?

No, because "strelka" in russian means simply arrow (e.g. on a clock), little arrow="strelochka".

Somebody discovered one of the Russian space dogs was named Strelka (the engine was named after a band, though). Many people probably looked it up on Wikipedia, and read:

Strelka means "little arrow" in Russian

Seeing as most people don't speak Russian, the misinformation was allowed to spread.

[Dariusz Orzechowski]

little arrow - strelka
arrow - strela

[Uri Blass]

The tables in question are present in virtually all bitboard programs, with some small variety depending on board layout. They are nothing more than precomputed bitboard masks for detecting passed pawns, doubled pawns, etc. Nothing very interesting.

Strelka's main function contains a big 'for' loop which iterates over all 64 squares of the board and XORs all entries of all bitboard arrays by Random[0][13]:

Code: Select all

  for (i = 0; i < 64; i++) {
    MaskPawnDoubled[i] ^= Random[0][13];
    MaskPawnIsolated[i] ^= Random[0][13];
    MaskPawnProtectedW[i] ^= Random[0][13];
    MaskPawnProtectedB[i] ^= Random[0][13];
    MaskPawnAttacksW1[i] ^= Random[0][13];
    MaskPawnAttacksB1[i] ^= Random[0][13];
    MaskPawnAttacksW2[i] ^= Random[0][13];
    MaskPawnAttacksB2[i] ^= Random[0][13];
    MaskPawnPassedW[i] ^= Random[0][13];
    MaskPawnPassedB[i] ^= Random[0][13];
    ...
  }

I have no why this is done, but it is difficult to believe that it is in an attempt to hide something, because none of the arrays involved are very original or interesting. They can all be found in lots of open source bitboard chess programs (including mine).

Tord

I wonder if the first significantly bigger array that is also xored is also used by lot of open source bitboard programs.

unlike you I did not read a lot about bitboard so I do not know and the first array with more than 1000 numbers that is xored is the first array that I find not easy to understand(I guess I may understand it in a few hours of investigations)

I can see that the first part of it is about diagnols but so far I do not see clear meaning of the values.

I am going to look at more values and try to write a program to calculate more numbers in that array and compare with the original array(inspite of not understanding it at this point of time I can see some rules with the numbers that help me to guess the next numbers).

Uri

[Graham Banks]

We cannot blame him of trying to hide similiarity to rybka and he even chose the name strelka that is similiar to rybka.

Uri

What is the similarity between fish and arrow?

The similiarity in the names is that both end with "ka"

Are there more chess programs that end with "ka" except rybka and strelka?

Uri

Anechka

[Aleks Peshkov]

A little Russian lesson.

rybochka, strelochka, Anechka = not necessary small, but a endearing (kind) name for ryba, strela, Anna. (-a is common for all feminine gender nouns, more then a third of russian nouns are grammatically feminine).

rybka, strelka, anka = not always means small in size, but possibly means less significant in importance and sometimes it is not a kind name.

Rybka (rybochka) is a kind name of a girl-friend.
Strelka is just a dog's name with no special kind meaning. Strelka has also or rare meaning of criminal or teens meeting.

Most Russian, Ukrainian and Belorussian programmers prefer to name engines in English because many Cyrillic words looks ugly in Latin letters.

Somebody discovered one of the Russian space dogs was named Strelka (the engine was named after a band, though).

Yes, Strelka become a popular name after a first dog cosmonaut. I doubt that Russian girlish pop-music band "Strelki" (plural, with meaning of girl's eye decoration) is a reasonable origin to name the engine.

[GenoM]

Chris
you just walking around
i think you're afraid to enter
i'm asking myself: why?

[Vempele]

I doubt that Russian girlish pop-music band "Strelki" (plural, with meaning of girl's eye decoration) is a reasonable origin to name the engine.

I see no reason why Sergei Markoff would have lied about it.

[Aleks Peshkov]

Strelki are painted stripes under women eyes.
Strelka also means a scratch stripe on spoiled stockings.
These translations comes in mind when we talk about girl pop-music band name. I doubt these are reasonable meaning for the engine.

Strelka also means rail-way switch-point or blade of grass.

[Christopher Conkie]

Chris
you just walking around
i think you're afraid to enter
i'm asking myself: why?

Do you support Lokomotiv or Botev Plovdiv?

[Aleks Peshkov]

Strelki band