Mona  vs  Patrick Duff (USA)                 Jan 8 - Feb 13, 2001

   1. d1-b3 a5-c7   2. b1-b4 a7-d7   3. g1-g3 c7:g3   4. g8-d5 h6:f8
   5. b8-b5 h4:e1   6. f1-c4 e1-c3   7. e8-a8 g3-e5   8. d8-c7 h5:d5
   9. c8:c3 e5:c3  10. a8-c6 f8-c5  11. c1:a3++

 Patrick is a relative newcomer to LoA, and clearly has a lot of talent.
 He scored a 5-2 record in the first round (in Mona's section), which
 included a very short upset over Claude Chaunier, thereby winning the
 tiebreak to advance to the final.

  Move by Move:

   1. d1-b3 a5-c7

      +-----------------+          +-----------------+
    8 | . B B B B B B . |        8 | . B B B B B B . |
    7 | W . . . . . . W |        7 | W . W . . . . W |
    6 | W . . . . . . W |        6 | W . . . . . . W |
    5 | W . . . . . . W |        5 | . . . . . . . W |
    4 | W . . . . . . W |        4 | W . . . . . . W |
    3 | W B . . . . . W |        3 | W B . . . . . W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . B B . B B B . |        1 | . B B . B B B . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 ply value  best  principle variation (last 4-ply deleted)

 11   +143  b1-b4 a7-d7 g1-g3 h3-e6 g3:c7 a6-d6 e1-e4
 13   +112  b1-b4 a7-d7 g1-g3 h2-f2 g8-d5 h7-e7 c1-c4 a6-c6 f1-d3

 A note on Mona's minimax scores:

 There is a significant odd-even effect, so odd-ply values are likely
 optimistic (at least 50 points too high, so +50 should be interpreted
 as an equal position).  A score of about +150 usually indicates a
 small advantage, and +300 a clear advantage.

 In these games, Mona indicates a mate threat with a +2000 bonus, so
 a score of +4150 indicates a small positional advantage with a double
 threat to connect.  Only certain types of mate threats are detected
 statically, so there could be more in a given position.  Mona reserves
 0 (zero) for a draw and +32000 for a win.

   2. b1-b4 a7-d7

      +-----------------+          +-----------------+
    8 | . B B B B B B . |        8 | . B B B B B B . |
    7 | W . W . . . . W |        7 | . . W W . . . W |
    6 | W . . . . . . W |        6 | W . . . . . . W |
    5 | . . . . . . . W |        5 | . . . . . . . W |
    4 | W B . . . . . W |        4 | W B . . . . . W |
    3 | W B . . . . . W |        3 | W B . . . . . W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . B B B . |        1 | . . B . B B B . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 11   +112  g1-g3 h2-f2 b8-b5 h3-e6 f1-c4 h7-e7 c1:a3
 13   +109  g1-g3 h3-e6 g3:c7 h7-e7 f1-d3 h6:f8 c8-c5 a6-c4 c7-f4

   3. g1-g3 c7:g3

      +-----------------+          +-----------------+
    8 | . B B B B B B . |        8 | . B B B B B B . |
    7 | . . W W . . . W |        7 | . . . W . . . W |
    6 | W . . . . . . W |        6 | W . . . . . . W |
    5 | . . . . . . . W |        5 | . . . . . . . W |
    4 | W B . . . . . W |        4 | W B . . . . . W |
    3 | W B . . . . B W |        3 | W B . . . . W W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . B B . . |        1 | . . B . B B . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 Patrick:  Mona's move surprised me.  Is she offering a sacrifice to
 lure me into a trap?

 Darse:  I'm not sure.  Your move c7:g3 wasn't in any of her main lines.
 There is no explicit term for material, so she wouldn't much care about
 losing a piece.  Mona does usually grab a free piece when it is possible
 though, because it usually improves other evaluation measures, like
 mobility.  She often plays g3:c7 in these types of positions, to reduce
 the White blockade and create a foothold into the center.  The c7:g3
 capture also relieves that pressure, so perhaps she thinks it is less
 attractive than other moves.  Of course, it could still be completely
 playable.

 11   +256  g8-d5 a3:c1 e1-c3 h4-e4 f1-d3 e4:b4 c8-c5
 13   +234  g8-d5 a3:c1 e1-c3 h3-d3 f8-f6 h4-e4 f6-d4 g3:c3 c8-c5

   4. g8-d5 h6:f8

      +-----------------+          +-----------------+
    8 | . B B B B B . . |        8 | . B B B B W . . |
    7 | . . . W . . . W |        7 | . . . W . . . W |
    6 | W . . . . . . W |        6 | W . . . . . . . |
    5 | . . . B . . . W |        5 | . . . B . . . W |
    4 | W B . . . . . W |        4 | W B . . . . . W |
    3 | W B . . . . W W |        3 | W B . . . . W W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . B B . . |        1 | . . B . B B . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 Patrick:  h2-e5 was also attractive, since it could tax Mona's search
 horizon.  In the end I decided that would be a bit unfair.

 Darse:  That would be perfectly fair, but it isn't easy to do.  We have
 found that the tactics in LOA are usually not as complex as they are
 in chess.  This is why YL does not have an advantage over Mona at long
 time controls.  YL still searches 2 or 3 ply deeper (20 times as many
 positions), but the better-informed (slow) evaluation function is worth
 more than that, once Mona is able to reach 11-ply or so.

 As a general rule, it will be fatal for any human to play into a highly
 tactical position against a deep searching program.  Even if it is an
 extremely complicated situation, the chances are that the program will
 handle it much better than any mere mortal.

 11   +298  b8-b5 a2-c2 c1-d2 h2-e2 d2-d6 h3:f1 e1-c3
 13   +259  b8-b5 a2-c2 e1-e3 a6:c8 c1-e1 f8-c5  ...   ...   ... 

   5. b8-b5 h4:e1

      +-----------------+          +-----------------+
    8 | . . B B B W . . |        8 | . . B B B W . . |
    7 | . . . W . . . W |        7 | . . . W . . . W |
    6 | W . . . . . . . |        6 | W . . . . . . . |
    5 | . B . B . . . W |        5 | . B . B . . . W |
    4 | W B . . . . . W |        4 | W B . . . . . . |
    3 | W B . . . . W W |        3 | W B . . . . W W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . B B . . |        1 | . . B . W B . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 11   +710  f1-c4 h3-e6 e8-a8 d7-b7 c1:a3 a2-c2 d8-c7
 13  +2189   ...   ...   ...   ...   ...   ...   ...   ...   ... 

 extended search:
 13  +2134  f1-c4 e1-c3 e8-a8 h5-e5 c8:a6 h3-g2 d8-c7 g2:d5 a6-b6

   6. f1-c4 e1-c3

      +-----------------+          +-----------------+
    8 | . . B B B W . . |        8 | . . B B B W . . |
    7 | . . . W . . . W |        7 | . . . W . . . W |
    6 | W . . . . . . . |        6 | W . . . . . . . |
    5 | . B . B . . . W |        5 | . B . B . . . W |
    4 | W B B . . . . . |        4 | W B B . . . . . |
    3 | W B . . . . W W |        3 | W B W . . . W W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . W . . . |        1 | . . B . . . . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 Patrick:  I think Mona has the better position at the moment.

 Darse:  Yes, she really excels in open positions like this one.  In
 fact, she could have proven the win this turn, but didn't finish 13-ply
 within the one billion node limit, and played this less efficient move
 instead.  [c1:a3 is the best positional move and also the quickest mate,
 but e8-a8 showed a better guaranteed threat at 11-ply]

 11  +1995  c1:a3 f8-c5 e8-b8 h5:d5 b8-a7 g3:b3 d8-b8
 11  +2134  e8-a8 h5-e5 c8:a6 h3-g2 d8-c7 g2:d5 a6-b6
 13  +2488   ...   ...   ...   ...   ...   ...   ...   ...   ... 

 extended search:
 13  +2488  e8-a8 g3-e5 c1:a3 h5:d5 c8-c5 e5-c7 a8-c6 h3-d3 d8-e7
 13 +32000  c1:a3 f8-c5 c8:a6 h5:d5 e8-c8 g3:b3 d8-b8 h3-d3 a6-b6

   7. e8-a8 g3-e5

      +-----------------+          +-----------------+
    8 | B . B B . W . . |        8 | B . B B . W . . |
    7 | . . . W . . . W |        7 | . . . W . . . W |
    6 | W . . . . . . . |        6 | W . . . . . . . |
    5 | . B . B . . . W |        5 | . B . B W . . W |
    4 | W B B . . . . . |        4 | W B B . . . . . |
    3 | W B W . . . W W |        3 | W B W . . . . W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . . . . . |        1 | . . B . . . . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 11  +2488  c1:a3 h5:d5 c8-c5 e5-c7 a8-c6 h3-d3 d8-e7
 13  +2313  c1:a3 h5:d5 c8-c5 e5-c7 a8-c6 a6:c6 d8-e7 h7-h4 e7-e6
 13  +2902  d8-c7 h5:d5 c8:c3 a6-b6 c3:e5 d5-d3 a8:a4 f8-c5 c1:c5

   8. d8-c7 h5:d5

      +-----------------+          +-----------------+
    8 | B . B . . W . . |        8 | B . B . . W . . |
    7 | . . B W . . . W |        7 | . . B W . . . W |
    6 | W . . . . . . . |        6 | W . . . . . . . |
    5 | . B . B W . . W |        5 | . B . W W . . . |
    4 | W B B . . . . . |        4 | W B B . . . . . |
    3 | W B W . . . . W |        3 | W B W . . . . W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . . . . . |        1 | . . B . . . . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

 11  +2902  c8:c3 a6-b6 c3:e5 d5-d3 a8:a4 f8-c5 c1:c5
 13 +32000  c8:c3 a6-b6 c3:e5 d5-d3 a8:a4 f8-c5 c1:c5 h3-g2 e5-d4

 Darse:  I don't think Mona's two quick wins with the Black pieces say
 anything negative about Patrick's play -- it may just be that his style
 leads to short games, one way or the other.  He has obviously had a lot
 of success with this sharp approach against human opponents.

   9. c8:c3 e5:c3

      +-----------------+          +-----------------+
    8 | B . . . . W . . |        8 | B . . . . W . . |
    7 | . . B W . . . W |        7 | . . B W . . . W |
    6 | W . . . . . . . |        6 | W . . . . . . . |
    5 | . B . W W . . . |        5 | . B . W . . . . |
    4 | W B B . . . . . |        4 | W B B . . . . . |
    3 | W B B . . . . W |        3 | W B W . . . . W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . . . . . |        1 | . . B . . . . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

  9 +32000  a8-c6 d5:b5 c6-d5 c3-g3 c1:a3 f8-c5 c7-b6 d7:d5 b6-a5

  10. a8-c6 f8-c5

      +-----------------+          +-----------------+
    8 | . . . . . W . . |        8 | . . . . . . . . |
    7 | . . B W . . . W |        7 | . . B W . . . W |
    6 | W . B . . . . . |        6 | W . B . . . . . |
    5 | . B . W . . . . |        5 | . B W W . . . . |
    4 | W B B . . . . . |        4 | W B B . . . . . |
    3 | W B W . . . . W |        3 | W B W . . . . W |
    2 | W . . . . . . W |        2 | W . . . . . . W |
    1 | . . B . . . . . |        1 | . . B . . . . . |
      +-----------------+          +-----------------+
        a b c d e f g h              a b c d e f g h  

  1 +32000  c1:a3

  11. c1:a3++

      +-----------------+
    8 | . . . . . . . . |
    7 | . . B W . . . W |
    6 | W . B . . . . . |
    5 | . B W W . . . . |
    4 | W B B . . . . . |
    3 | B B W . . . . W |
    2 | W . . . . . . W |
    1 | . . . . . . . . |
      +-----------------+
        a b c d e f g h