Jorge Gómez Arrausi (Spain)  vs  Mona        Jan 8 - Feb 28, 2001

   1. b1-b3 h4-f2   2. e8-g6 a2-d2   3. b8-b6 h2-e2   4. c1-c3 a6-d3
   5. g6:d3 a7-c7   6. f8-f5 a3-b4   7. f5:f2 h3:d3   8. g8-g6 a4-c4
   9. g6:d3 c7:c3  10. e1-g3 h7-f5  11. g3:c3 f5:f2  12. d8-d4 h5-f5
  13. d3:f5 h6-g7  14. c3-f6 g7-g5  15. f1-c1 c4:c1  16. f5-e4 g5-g3
  17. c8-d7 a5-b5  18. e4:e2 b4:d4  19. Resigns (mate in five moves)

  Jorge Gómez Arrausi is arguably the best human LoA player in the
  world.  He is the defending e-mail champion (he tied for first place
  with Kerry Handscomb, but won the game between them), and he cruised
  to a 7-0 record in the qualifying round this year.

  Jorge's strength is in the middlegame and endgame play.  Having looked
  at several of his games using Mona, I can verify that his finishing
  technique is almost perfect (by far the best of anyone I have seen).
  His intuition and judgement in this game were very impressive, and he
  fought valiantly before finally succumbing to the silicon beast.

  Move by Move:

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

   1. b1-b3 h4-f2

 Darse:  1... h4-f2 is a new opening book move for Mona, based on
 deeper searches of all the main candidate moves and replies.

 Jorge:  I was expecting the very interesting h3-e3.

 Darse:  She doesn't like that move too much, which is interesting
 because that was exactly the style I was striving for during the
 development of the program (active, efficient, central, etc).  There
 could be deeper reasons for disliking it though.  Perhaps the reply
 e8-g6 is just too strong, making a nice developing move while also
 threatening e1:e3.

      +-----------------+          +-----------------+
    8 | . B B B B B B . |        8 | . B B B . B B . |
    7 | W . . . . . . W |        7 | W . . . . . . W |
    6 | W . . . . . . W |        6 | W . . . . . B W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | W . . . . . . . |        4 | W . . . . . . . |
    3 | W B . . . . . W |        3 | W B . . . . . W |
    2 | W . . . . W . W |        2 | W . . . . 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  

   2. e8-g6 a2-d2

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

 11     +6  a2-d2 b8-b6 a7-c7 f8-f5 h5-f3 d1:f3 h2-e2
 11    +15  h2-e2 d8-b6 a2-d2 b6:f2 h7-f7 g8-g5 a3:c1
 13     -7  h2-e2 b8-b6 h3-e3 f1-g2 a3:c1 g1:c1 f2:b6 g8-g5 a2-d2
 13     -1  a2-d2 b8-b6 a7-c7 g1-g4 h5-f5 g8-g5 h2-e2 d1:a4 e2:g4

 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.

      +-----------------+          +-----------------+
    8 | . B B B . B B . |        8 | . . B B . B B . |
    7 | W . . . . . . W |        7 | W . . . . . . W |
    6 | W . . . . . B W |        6 | W B . . . . B W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | W . . . . . . . |        4 | W . . . . . . . |
    3 | W B . . . . . W |        3 | W B . . . . . W |
    2 | . . . W . W . W |        2 | . . . W . 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  

   3. b8-b6 h2-e2

 Jorge:  I am feeling Mona's sharp style.  She moves the piece with no
 more escapes.  If I play g8-g5, a3:c1 is a good cross-corner capture.
 If I attack d8-d5, a7-d4 is strong.

 Darse:  Yes, Mona does quite a bit of analysis to determine the least
 mobile piece for each side.  We wouldn't want a clever human to earn a
 cheap victory just by trapping a piece -- they must fight on a dynamic
 battleground, full of possibilities! :-)

 13     -6  a7-c7 g1-g4 h5-f5 g8-g5 a3:c1 d8-d5 a4-b5 f1-c4 c1:g5
 13     +6  h2-e2 b6:f2 h6-e3 g8-g5 h7-f7 d8-d5 d2:d5 g1-g4 h3-d3

      +-----------------+          +-----------------+
    8 | . . B B . B B . |        8 | . . B B . B B . |
    7 | W . . . . . . W |        7 | W . . . . . . W |
    6 | W B . . . . B W |        6 | W B . . . . B W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | W . . . . . . . |        4 | W . . . . . . . |
    3 | W B . . . . . W |        3 | W B B . . . . W |
    2 | . . . W W W . . |        2 | . . . W W W . . |
    1 | . . B 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  

   4. c1-c3 a6-d3

 Jorge:  My golden rule for the opening is: if somebody blocks you, you
 will have to block them.  Mona is very intelligent and I have a lot of
 problems in order to block her.  With c1-c3 I prevent c3:a1 and a5 can
 not defend d2 of an eventual attack with d8 and f8.  It also prevents
 h6-e3.  I think Mona will not move h5 but I am concerned about a6-d3.

 Darse:  Mobility is a very large term in her evaluation function, so she
 will generally chose the line that guarantees the most active position.
 I don't know if that is "intelligent", but I'm certainly guilty of worse
 anthropomorphization.  :-)

 11   +108  a6-d3 b6:f2 h3:c3 g8-g5 h7-f7 f1-f5 a4-b4
 13    +91  a6-d3 b6:f2 h3:c3 g8-g5 d3:g6 g5:d2 a5-c7 d8-e7 a7:e7

      +-----------------+          +-----------------+
    8 | . . B B . B B . |        8 | . . B B . B B . |
    7 | W . . . . . . W |        7 | W . . . . . . W |
    6 | . B . . . . B W |        6 | . B . . . . . W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | W . . . . . . . |        4 | W . . . . . . . |
    3 | W B B W . . . W |        3 | W B B B . . . W |
    2 | . . . W W W . . |        2 | . . . W 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  

   5. g6:d3 a7-c7

 Jorge:  I think g6:d3 is the obvious move.  Surely, Mona will play a3-c5
 and a tactical battle has just started.  I have not found a proper answer
 to a3-c5, it is difficult.

 Darse: Mona's main line was b6:f2 h3:c3 g8-g5, but YL agrees with g6:d3,
 so your move is also strong.  It seems she doesn't like a3-c5 c8:c5 h3:d3
 g8-g6 (or f8-f5) very much.  I guess a7-c7 develops an awkward piece, and
 starts to build the attack on the third rank pieces (but that's just my
 speculation, not Mona's).  In any case, it does look like it is becoming
 a fairly sharp position.

 11   +131  a7-c7 b6-b4 a3-a6 b3-b5 h3-f5 b5:f5 a4-b5
 13   +122  a7-c7 b6-b4 a3-a6 b3-b5 h3-f5 b5:f5 a4-b5 f5:b5 a5:d8

      +-----------------+          +-----------------+
    8 | . . B B . B B . |        8 | . . B B . . B . |
    7 | . . W . . . . W |        7 | . . W . . . . W |
    6 | . B . . . . . W |        6 | . B . . . . . W |
    5 | W . . . . . . W |        5 | W . . . . B . W |
    4 | W . . . . . . . |        4 | W . . . . . . . |
    3 | W B B B . . . W |        3 | W B B B . . . W |
    2 | . . . W W W . . |        2 | . . . W 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  

   6. f8-f5 a3-b4

 Jorge:  My first intuition said 5. b6:f2 but I considered my piece on
 c3 to be very important and I forgot about this move immediately.  My
 a3-c5 idea was good, but Mona's is better because she is threatening
 a3-c5! on the next move.  I have no good moves.  Mona has clear advantage
 now.  I expect she will answer h6-f4 or h7-f7 (if f2:f5 I reply f1:h3).

 Darse:  The hop is shorter now, but I guess she still likes the a3 plan.

 11   +148  a3-b4 b3-f3 a4-b5 g8-g6 b5:f5 c8:f5 h3:f5
 13   +125  a3-b4 b3-f3 b4:b6 d1-b3 h6-f4 g8-e6 h5-g6 g1-g3 b6:e6

      +-----------------+          +-----------------+
    8 | . . B B . . B . |        8 | . . B B . . B . |
    7 | . . W . . . . W |        7 | . . W . . . . W |
    6 | . B . . . . . W |        6 | . B . . . . . W |
    5 | W . . . . B . W |        5 | W . . . . . . W |
    4 | W W . . . . . . |        4 | W W . . . . . . |
    3 | . B B B . . . W |        3 | . B B B . . . W |
    2 | . . . W W W . . |        2 | . . . W W B . . |
    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  

   7. f5:f2 h3:d3

 Darse:  The interplay between f2, d3, and c3 becomes a recurring theme.
 Mona prefered 7. b3-f3 primarily because the b3 piece becomes completely
 immobile in the game continuation.

 11   +201  h3:d3 g8-g6 h7-f7 c8-d7 d2:d7 b6-e6 h6-g5
 13   +203  h3:d3 g8-g6 a4-c4 c8-d7 d2:d7 g6:d3 d7:d3 c3-d4 h6-h3

      +-----------------+          +-----------------+
    8 | . . B B . . B . |        8 | . . B B . . . . |
    7 | . . W . . . . W |        7 | . . W . . . . W |
    6 | . B . . . . . W |        6 | . B . . . . B W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | W W . . . . . . |        4 | W W . . . . . . |
    3 | . B B W . . . . |        3 | . B B W . . . . |
    2 | . . . W W B . . |        2 | . . . W W B . . |
    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  

   8. g8-g6 a4-c4

 Darse:  The threat to d3 is answered with a threat to c3.

 11   +167  h7-f7 f1-f4 f7:f4 g1-d4 h6-e3 d8:d3 h5-f5
 11   +203  a4-c4 c8-d7 d2:d7 g6:d3 d7:d3 c3-d4 h6-h3
 13   +205  a4-c4 c8-d7 d2:d7 d8-e7 c7-d6 c3-d4 d3:g6 g1-c5 d6-e5

      +-----------------+          +-----------------+
    8 | . . B B . . . . |        8 | . . B B . . . . |
    7 | . . W . . . . W |        7 | . . W . . . . W |
    6 | . B . . . . B W |        6 | . B . . . . . W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | . W W . . . . . |        4 | . W W . . . . . |
    3 | . B B W . . . . |        3 | . B B B . . . . |
    2 | . . . W W B . . |        2 | . . . W W B . . |
    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  

   9. g6:d3 c7:c3

 11   +319  c7:c3 e1-g3 h7-f5 g3:c3 f5:d3 g1-d4 h6-h4
 13   +238  c7:c3 e1-g3 h7-f5 g3:c3 f5:d3 g1-d4 h6-h4 d8:d3 h5-f5

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

  10. e1-g3 h7-f5

 Jorge:  My position is painful.  I will try my last hope.  If Mona has a
 strong reply, I'll meditate my retirement.  I have to spend my neurons
 on other (more hopeful) games.  On the other hand, I would have to admit
 a humiliation, so I don't know.

 Darse:  There is no shame in losing when you have played with honour.
 Although I'm proud of my young protégée, she truly is inhuman!

 13   +217  h7-f5 g3:c3 f5:f2 d8-d4 b4-c5 f1-g2 a5-d5 c3-e5 c5-d6
 15   +161  h7-f5 g3:c3 f5:f2 c8-c5 h5-h3 b6:f2 h3:d3 g1-d4 d2-f4 d1-b1 h6-g6

 Darse:  Jorge's 10. e1-g3! is a truly excellent move -- perhaps the best
 I have witnessed in any game against Mona.  I was very tempted to tell
 Jorge that during the game, but decided it wouldn't be fair to the other
 players in the tournament.  Mona's score jumps to over +300 after any
 other move, but actually drops a bit after e1-g3, and Black obtains a
 position with lots of practical chances.  Since the scores at shallower
 depths are quite a lot higher, it looks like this move is the product of
 some very deep analysis.  Jorge is obviously a worthy opponent!

 - if Black plays 10. b6-d6:
 13   +379  h6-f6 f2-f5 f6:d6 g1-f2 a5-c7 f1-f4 h5:f5 f2:f5 c7:f4
 13   +436  h6-f4 f1:f4 h7-f5 f2:f5 e2-e4 d1-a1 a5-d5 d6-e6 c3-e5

 - if Black plays 10. g1-d4:
 13   +325  a5-c5 b6-d6 h7-f5 d3:f5 c5:f5 d8-e7 h6-f4 d6:d2 f4:d2
 13   +329  h7-g7 d1-a1 g7-g6 d4-g4 h6-g7 c8-c5 b4-e4 b3-c2 a5:e1

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

  11. g3:c3 f5:f2

 11   +217  f5:f2 d8-d4 b4-c5 f1-g2 a5-d5 c3-e5 c5-d6
 13   +161  f5:f2 c8-c5 h5-h3 b6:f2 h3:d3 g1-d4 d2-f4 d1-b1 h6-g6

 13   +160  f5:d3 g1-d4 h6-h4 d8:d3 h4:d4 b3-e3 h5-h6 e3-e5 b4-e4

 Jorge:  I expected f5:f2 after g3:c3, but I thought Mona could have
 played 11... f5:d3.  It appears Mona is a natural born blocker.

 Darse:  f5:f2 was preferred over f5:d3 by only one point (13-ply +160).
 11... f5:d3 looks like it leads to a much cleaner win.  Playing both
 sides of the position with Mona suggests that the following line may be
 highly forcing:
 11. g3:c3 f5:d3  12. g1-d4 h6-h4  13. d8:d3 h4:d4  14. b3-e3 h5-h6
 15. f2-f4 b4:f4  16. f1-f3 h6-f6  17. e3-e5 a5-c5  18. f3-e4 f4-f2
 and White has a won position (mate in at most six more moves each)

 After 11... f5:f2, Black has more options for each move, and more of a
 fighting chance.  Perhaps I have the blocking factors set a bit too high.

      +-----------------+          +-----------------+
    8 | . . B B . . . . |        8 | . . B . . . . . |
    7 | . . . . . . . . |        7 | . . . . . . . . |
    6 | . B . . . . . W |        6 | . B . . . . . W |
    5 | W . . . . . . W |        5 | W . . . . . . W |
    4 | . W W . . . . . |        4 | . W W B . . . . |
    3 | . B B B . . . . |        3 | . B B B . . . . |
    2 | . . . W W W . . |        2 | . . . W 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  

  12. d8-d4 h5-f5

 11   +180  b4-c5 f1-g2 a5-d5 c3-e5 c5-d6 b3-b5 d5-b3
 11   +207  h5-f5 f1-c1 b4-c5 d3:f5  ...   ...   ... 
 13   +186  h5-f5 f1-c1 b4-c5 d3:f5 a5-d5 g1-g2 f2-e1 f5-f4 e2-e4

 Jorge:  This is the kind of position I usually play well.  Unfortunately,
 Mona has a huge advantage already.  I also considered 12. c8-c5 b4-d4
 13. d1-a1, but this last move is unintuitive.

 Darse:  I looked at this move as well, and Mona would have played b4-d4.
 The d1-a1 reply isn't her PV move, but it is for YL, so it is undoubtedly
 strong (the programs have natural biases against corner moves, so if one
 gets selected, it is almost always worthwhile).

 - if Black plays 12. c8-c5:
 13   +166  h5-h3 b6:f2 h3:d3 g1-d4 d2-f4 b3-b1 h6-g6 d8-c8 e2-c2
 13   +196  b4-d4 b6-b4 a5-c7 d3-e4 c7-d6 c5-e5 h6-f6 f1-g2 h5-f5

      +-----------------+          +-----------------+
    8 | . . B . . . . . |        8 | . . B . . . . . |
    7 | . . . . . . . . |        7 | . . . . . . . . |
    6 | . B . . . . . W |        6 | . B . . . . . W |
    5 | W . . . . W . . |        5 | W . . . . B . . |
    4 | . W W B . . . . |        4 | . W W B . . . . |
    3 | . B B B . . . . |        3 | . B B . . . . . |
    2 | . . . W W W . . |        2 | . . . W 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  

  13. d3:f5 h6-g7

 11   +229  h6-g7 c3-e3 f2:f5 b6-c6 c4-e6 c6:e6 b4:d4
 13   +236  h6-g7 c3-e3 f2:f5 f1-f3 f5:f3 c8-c6 g7-h6 g1-e1 a5:e1

 Jorge:  Through a time I have believed I can still win.  Mona's next
 move will be crucial.  It could be the inflection point of the game.
 I overlooked 12... h5-f5, I thought 12... a5-c5 was the main line.
 I have no other reasonable answer.

 Darse:  Jorge's optimism is well-founded, since some of the self-play
 "roll-outs" show attacks by White ending in a draw (perpetual check).
 12... a5-c5 is probably a more solid move, whereas h5-f5 is more of a
 gamble, and puts more pressure on Black.  With a nice positional edge,
 it might be safer to go with the solid choice.

 It looks like 13. f1-c1 makes a threat that has to be answered, but
 the score after playing d3:f5 on the next move is pretty much the same.

 - if Black plays 13. f1-c1:
 13   +208  b4-c5 d3:f5 a5-d5 g1-g2 d5-f3 g2-h3 h6-e3 f5-e4 f2-f4
 15   +235  b4-c5 d3:f5 h6-e3 g1-g2 f2-g3 g2-f3 e2-e4 b3-b5 a5-a4 d1-b3 d2:d4


 Jorge:  The only time I beat Mona's applet was with a clear material
 advantage, and this has been my objective since my first move.  I think
 that with a clear material advantage I can make the game longer and Mona
 may lose her advantage.  But I'm not sure, because the applet strength
 is not the actual strength.

 Darse:  Jorge's comments are interesting because I've always assumed
 that Mona's play is better closer to the end of the game (since it is
 perfect for the last seven moves or so).  He believes her advantage is
 much earlier in the game, when the position is still very complicated.
 This could be especially true against Jorge, because he might be the
 only player in the world who can compete on an equal footing late in
 the game.  On the other hand, a player like Kerry Handscomb might be
 able to outplay her strategically in the opening, and thus obtain a
 very good position.  Perhaps working together they would defeat Mona.

 The maximum time on the applet (http://sass-lake.cs.ualberta.ca/games/loa/)
 is two minutes per move, which is usually enough for 7-ply or 9-ply.
 In these e-mail games Mona searches for one billion nodes (about eight
 hours on a faster machine), which is usually enough to reach 13-ply,
 and is therefore substantially stronger.


 Darse:  Mona is usually quite greedy, even though she gives no extra
 value for material.  Winning pieces usually helps other terms of the
 evaluation.  Ironically, she gave up material in most of the games in
 the final, but apparently for more valuable positional factors, since
 all of those games were quick wins.  For example, the game against
 Patrick Duff was a won position after only six moves each.

 Jorge:  Yes!  That is quite usual, for example hthordsen-kerryh or
 jarrausi-kerryh in the fourth (1999) e-mail tournament.  A player may
 offer pieces for a strong attack, but if the attack fails, the attacker
 will be in trouble.  (And this is what I am looking for in this game).

      +-----------------+          +-----------------+
    8 | . . B . . . . . |        8 | . . B . . . . . |
    7 | . . . . . . W . |        7 | . . . . . . W . |
    6 | . B . . . . . . |        6 | . B . . . B . . |
    5 | W . . . . B . . |        5 | W . . . . B . . |
    4 | . W W B . . . . |        4 | . W W B . . . . |
    3 | . B B . . . . . |        3 | . B . . . . . . |
    2 | . . . W W W . . |        2 | . . . W 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  

  14. c3-f6 g7-g5

 11   +273  g7-g5 f1-c1 f2:f5 b3-c3 b4-c5 c8-e6 a5-e5
 13   +467  g7-g5 f1-c1 c4:c1 b3-c4 c1:c4 f6-h6 b4-b2 d4-f6 b2-c1

 Jorge:  I overlooked h6-g7 too.  I would like to play b6:f2 g7:d4 g1:d4
 but I think I can not defend.  With c3-f6 I weaken my position.  This
 is a signal that I have already lost, and all the rest is pure anguish.
 Furthermore Mona can devise a mate at any moment, perhaps now.

 Darse:  I was again tempted to tell Jorge that his judgement was perfect,
 as 14. b6:f2 does indeed lose to g7:d4 g1:d4 e2-b2.  However, I held my
 tongue because b6:f2 is still a legal move in the position.

 The sudden 200-point jump in the score indicates that Black will soon
 be forced to make positional concessions if he wants to prevent White
 from getting a guaranteed threat of connection.  Normally the mate
 threat will be ensured on the next move anyway, so sometimes the best
 one can do is allow the threats and hope the attack fails.  Often a
 position will continue to deteriorate regardless of how well one plays,
 and it looks like this is the situation Jorge now faces in this game.

 Mona expected c3-e3 (and would grab back the piece with f2:f5), but
 self-play roll-outs show Black losing no matter what defence is tried.

 - if Black plays 14. b6:f2:
 11  +4205  g7:d4 g1:d4 e2-b2 c8-b8 b2-a3 f2-e1 d2-c2 d4-b2 c2-e4 c3-f3 c4-c5
 13 +32000  g7:d4 g1:d4 e2-b2 c8-b8 b2-a3 f2-e1 d2-c2 d4-b2 c2-e4 c3-f3 a3-c5 f5-f2 e4-d3

 - if Black plays 14. c3-e3:
 11   +236  f2:f5 f1-f3 f5:f3 c8-c6 g7-h6 g1-e1 a5:e1
 13   +244  f2:f5 f1-f3 g7-h6 e3-e5 f5:f3 g1-h2 h6-h4 h2-f4 h4-h5

 Sample self-play roll-outs:

 14. c3-e3 f2:f5  15. f1-f3 g7-h6  16. b6-f2 h6:e3  17. b3:e3 f5-d5 -+
 (c8-c6 a5-c5 d1-c2 d5-b3 f3-c3 d2:d4 c6-d6 c5-d5 g1-g2 e2-f3 g2-d2 b4-e4)

 14. c3-e3 f2:f5  15. f1-f3 g7-h6  16. e3-e5 f5:f3  17. b6-d6 b4:d6
 18. b3-b4 a5-c5 -+  (c8:c5 h6-f4 g1-g2 e2-e4 c5-e3 d2-f2 d1:f3 d6:d4
 g2-g3 f2-e2 g3-d3 c4-c3 b4-c5 e2-d2)

 14. c3-e3 f2:f5  15. f1-c1 a5-c5  16. c8-e6 c4:c1  17. d4-f6 c1-c3
 18. b3-d5 c3:f6 -+  (d1-c2 g7-e5 b6:b4 c5-c3 c2-e4 f6-f4 d5-f3 e2-d3
 e6-d5 d2:d5 g1-g2 c3-c4)

      +-----------------+          +-----------------+
    8 | . . B . . . . . |        8 | . . B . . . . . |
    7 | . . . . . . . . |        7 | . . . . . . . . |
    6 | . B . . . B . . |        6 | . B . . . B . . |
    5 | W . . . . B W . |        5 | W . . . . B W . |
    4 | . W W B . . . . |        4 | . W W B . . . . |
    3 | . B . . . . . . |        3 | . B . . . . . . |
    2 | . . . W W W . . |        2 | . . . W 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  

  15. f1-c1 c4:c1

 11   +467  c4:c1 b3-c4 c1:c4 f6-h6 b4-b2 d4-f6 b2-c1
 13  +1927  c4:c1 f5-e4 g5-g3 b3-c4 c1-e3 b6:b4 a5-b6 b4:d2 b6-d6

 Jorge:  15. f1-c1 is quite clear to me, since any other move permits
 g5-e3 and c8-e6 allows c4-c3.  I have to press Mona's weakest piece.
 I am not optimistic at all.

 Darse:  Yes, f1-c1 is definitely the best move.

 - if Black plays 15. b6:f2:
  7 +32000  g5-e3 b3-d3 b4-b3 f2-e1 a5-a4 f1-f4 e2-c2

 - if Black plays 15. b3-c3:
 13  +2231  g5-e3 b6:b4 a5-c5 b4-b3 c4:f1 f6:f2 f1-d3 b3-c4 e2-e4

 - and after 15. b3-c3 g5-e3  16. b6:b4:
 13  +4339  a5-c5 b4-b3 c4:f1 f6:f2 f1-d3 b3-c4 e2-e4 f5-d5 e3-e5 c3-a3 c5:a3 d5-b3 a3-b2
 13 +32000  a5-a4 d1-b3 d2:d4 b3:e3 a4-b3 f1-d1 d4-d2 g1-g2 c4-e4 f6-g6 b3:d1 c8-c6 d1-d3

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

  16. f5-e4 g5-g3

 11  +1927  g5-g3 b3-c4 c1-e3 b6:b4 a5-b6 b4:d2 b6-d6
 13  +2141  g5-g3 b3-c4 b4-e1 b6-b5 c1:c4 c8-c6 e1:e4 b5-b4 e4-d3

 Jorge:  What do you think, if I say that I can not do better that this?
 I compare this game with a chess player who promotes four pawns to queens
 to beat me.  Mona is playing with me!!  I took other moves in consideration
 (for example b6:f2), but finally I chose my first intuition.

 Darse:  I think your intuition is impeccable.  This is once again the
 best try defensively (several moves lose immediately).  She sees many
 threats in the near future, but cannot see the finish yet, due to your
 stubbornness and precision.  There may not be a way to save the position,
 but no one will doubt your expertise when they see the analysis!

 - if Black plays 16. b6:f2:
 13 +32000  b4:d4 b3-c3 a5-d5 f2-g3 c1-f4 g1-e3 g5:g3 f5-e4 e2-d3 f6:f4 g3-g4 c8-c6 g4-e2

 - if Black plays 16. b3-c3:
 13  +4125  b4:d4 b6-b5 g5-g3 g1:g3 d4:d1 b5-b4 c1-b2 b4:b2 f2-e3
 and mate is proven on the next move

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

  17. c8-d7 a5-b5

 11  +2498  a5-b5 f6-f4 g3-e3 e4-d3 e2-b2 b6-a6 f2-c2 d7:d2 b2:d4 b3-c4 b4:d2
 13 +32000  a5-b5 f6-f4 g3-e3 e4-d3 e2-b2 b6-a6 b2:d4 b3:e3 d4-c3 f4-h4 b5-a5 a6-c4 a5-e1

 Jorge:  I had two candidates: a) e4:b4 and b) c8-d7.  I prefered a)
 because I could keep the piece on a5 isolated and I was two pieces
 ahead too.  But I saw c1-e3 and I didn't find a solid answer.  Finally,
 I chose option b) -- it appears to be more dangerous and more difficult
 to understand.  My piece on d7 can enter the play with an eventual d7-d3.
 I am expecting e2:e4.  I would be happy if Mona keeps her chain of five
 pieces connected.

 Darse:  I did a search on e4:b4, and it loses in at most six moves after
 a5-b5.  I also looked at b6:f2, which again fails to mate in 13-ply.
 I agree that c8-d7 does look trickier and more optimistic -- it would be
 a fine choice against any human opponent.  Unfortunately, Mona is able
 to search beyond all of the tactics, proving a win in 13-ply with a5-b5.

 Some of the sample lines include:

 g1:g3 b5-d3 g3:d3 f2-c2 b6-c7 e2-b2 c7-e7 c1-c3

 b6:f2 g3-e3 b3-d3 e2-b2 d7:d2 b5:d3 f6-c3 c1:c3
 b6:f2 g3-e3 e4-d3 b4:d4 b3:e3 d2-c3 d1-c2 b5-b4 d7:d4 b4-d2

 b3-d3 b5-b2 b6-d6 c1-c2 e4:e2 c2-c3 g1-e1 f2:d4 e1-e3 g3-e5
 b3-d3 b5-b2 b6-d6 c1-c2 d7-c6 b2-c1 d3-b3 c1-e3 b3:e3 b4-b3

 e4:e2 b4:d4 e2-e3 g3-e1 e3:e1 b5-c4 f6-f4 c1-c3 b3-b1 f2:b6 g1:d4 b6:d4
 e4:e2 b4:d4 b3-d3 c1-e3 f6:d4 g3:d3 b6-a6 b5-b4 e2-g4 b4-b3 a6-c4 b3:d1

 f6-f4 g3-e3 b3-d3 b5-b2 d7:d2 b4:d2
 f6-f4 g3-e3 e4-d3 e2-b2 b3:e3 f2-c2 g1-c5 c1-a3
 f6-f4 g3-e3 e4-d3 e2-b2 g1-g2 b5:d3 d7-e7 b2:d4 f4:f2 d3-c4
 f6-f4 g3-e3 e4-d3 e2-b2 d1-e2 b2:d4 b3:e3 d4-c3 g1-e1 c1:e1
 f6-f4 g3-e3 e4-d3 e2-b2 b6-a6 b2:d4 b3:e3 d4-c3 f4-h4 b5-a5 a6-c4 a5-e1

 In many of these lines, Mona sacrifices quite a lot of positional value,
 but only because she has just enough maneuvering room left to ensure the
 mate.  Incidentally, Mona's PV move was b3-c4, but only because it hangs
 on for one extra move.  After b4-e1, mate would be announced on the next
 turn regardless (eg. b6-b5 c1:c4).  It looks like there was no possible
 escape, as of several moves ago, despite your near-perfect play.

 - if Black plays 17. b6:f2:
 13 +32000  g3-e3 e4:b4 e2-d3 c8-c6 a5-a4 c6-c4 d2:b4 c4-c2 a4:d4 f6:d4 b4-c3 b3-c4 c1-b2

 - if Black plays 17. e4:b4:
 13 +32000  a5-b5 b3-c4 c1:c4 b6:f2 g3-f3 c8-c6 b5-c5 d1-c2 f3-e3 c2-d3 e2-e4 f6-g5 c4-d5

 - if Black plays 17. b3-c4:
 11  +2141  b4-e1 b6-b5 c1:c4 c8-c6 e1:e4 b5-b4 e4-d3
 13  +2232  b4-e1 b6-b5 c1:c4 c8-c6 c4-c2 d4-b4 a5-a4 d1-a1 e2-c4

 - after 17. b3-c4 b4-e1  18. b6-b5:
 13 +32000  c1:c4 c8-c6 a5-a4 d1-b3 a4-a3 g1:g3 c4-c2 d4:d2 a3-b2 e4:c2 b2-d4 b3-d3 e1-e3

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

  18. e4:e2 b4:d4

 11 +32000  b4:d4 b3-d3 c1-e3 f6:d4 g3:d3 b6-a6 b5-b4 e2-g4 b4-b3 a6-c4 b3:d1

 Jorge:  Congratulations.  I like to permit the mate to my opponents. 
 Thank you very much for the game, the experience will be unforgettable.

 Darse:  Thank you.  Likewise for me.

 Jorge:  I am afraid I will be the last human champion.

 Darse:  There will always be a human champion, and it is a worthy title.
 Whether some computer program is better isn't really relevant.  If Mona
 wins with a perfect score, computer programs will likely be retired from
 future e-mail tournaments, which I happen to agree with.  I'm glad Mona
 was given the chance to prove herself against the best human players,
 but there isn't much point in future contests, at least until she loses
 a game.

 Jorge:  When Mona played against Kerry, Mona's program was different.
 I wonder if the old Mona would have won the tournament.

 Darse:  The old version did not have as much emphasis on blockades, which
 helps complicate the position, and might allow the opponent more chances
 to make an error (which they must do to lose with the Black pieces).
 However, I believe the program would still be extremely strong playing
 a more tactical style, with moves directly into the center.

 Jorge:  I think I have proven again that Mona wins in the opening and
 in the middle game -- in the endgame she just play correctly.  I think
 a human makes more mistakes with a higher number of pieces.

 Darse:  I had always assumed that the endgame phase would be Mona's
 biggest advantage, and I still believe that you are the only player who
 can compete with programs at this stage.  Perhaps others will learn from
 your technique.  It is encouraging to know that she also plays quite well
 in the earlier stages of the game.  I've always had some doubts...

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

  19. Resigns

 Jorge:  I resign.  I know the solution (e2-e3 g3-e1 e3:e1 b5-c4 f6-f4
 c1-c3 b3-b1 f2:b6 g1:d4 b6:d4) and to follow the game is pointless.
 (In addition, Mona will not appreciate the pleasure of a mate).


  Remaining moves of the principle variation:

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

  19. e2-e3 g3-e1

  9 +32000  g3-e1 e3:e1 b5-c4 f6-f4 c1-c3 b3-b1 f2:b6 g1:d4 b6:d4

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

  20. e3:e1 b5-c4

  7 +32000  b5-c4 f6-f4 c1-c3 b3-b1 f2:b6 g1:d4 b6:d4

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

  21. f6-f4 c1-c3

  5 +32000  c1-c3 b3-b1 f2:b6 g1:d4 b6:d4

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

  22. b3-b1 f2:b6

  3 +32000  f2:b6 g1:d4 b6:d4

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

  23. g1:d4 b6:d4++

  1 +32000  b6:d4

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