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Pentago Is a First-Player Win

Posted by timothy on from the heads-I-win-tails-you-lose dept.

First time accepted submitter jwpeterson writes "Like chess and go, pentago is a two player, deterministic, perfect knowledge, zero sum game: there is no random or hidden state, and the goal of the two players is to make the other player lose (or at least tie). Unlike chess and go, pentago is small enough for a computer to play perfectly: with symmetries removed, there are a mere 3,009,081,623,421,558 (3e15) possible positions. Thus, with the help of several hours on 98304 threads of Edison, a Cray supercomputer at NERSC, pentago is now strongly solved. 'Strongly' means that perfect play is efficiently computable for any position. For example, the first player wins."

8 of 136 comments (clear)

  1. Comparison to Chess? by jratcliffe · · Score: 4, Interesting

    Out of curiousity, does anybody know what the number for chess that compares to the 3e15 number for pentago is? In other words, how much "bigger" is chess?

    1. Re:Comparison to Chess? by vux984 · · Score: 5, Informative

      chess
      state space complexity 10^47

      go
      9x9 - 10^38
      13x13 - 10^79
      19x19 - 10^171

    2. Re:Comparison to Chess? by Anonymous Coward · · Score: 4, Informative

      According to the summary, 3e15 is the number of possible positions. The number of possible positions in chess is around 4e46.

      http://en.wikipedia.org/wiki/Shannon_number

  2. Chess by Anonymous Coward · · Score: 5, Funny

    After playing in chess tournaments for 20 years, I have strongly solved that chess is a forced win for any player facing me.

  3. Re:different than tic tac toe or connect 4? by mrchaotica · · Score: 4, Informative

    No, tic-tac-toe is always a tie.

    --

    "[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz

  4. Re:Grammar? by zerosomething · · Score: 5, Funny

    Can't the editors write a headline that meets the basic rules of grammar? How about "In the game of Pentago the first player can always win", or "Pentago is strongly solved".

    No cause with out those grammar mistakes their would be 30 pricent fuer com-mints on /.

    --
    It all starts at 0
  5. Wargames... by Rhaban · · Score: 5, Funny

    If Matthew Broderick had played pentago, the computer would have concluded the first country launching a nuclear missile always wins the war.
    Il came close

  6. Re:Grammar? by Anonymous Coward · · Score: 5, Funny

    No, now that Pentago is solved, we're reduced to online games of Pedant.

    HINT: Last player always wins.