Ticket #147 (new defect)

Opened 5 years ago

Last modified 3 years ago

double threat test cases, in hope of future implementation

Reported by: alain Owned by: gnugo
Priority: lowest Milestone: 3.9.x
Component: source Version:
Severity: normal Keywords:
Cc: patch: no

Description (last modified by alain) (diff)

Testcases of double threat move, not yet implemented in GNU Go. (examples found on computer-go list or on KGS).

  • Double ladder breaker, from Rémi Coulom and John Tromp.
  • Life with miai move by Sanghyeon Seo.
  • 3 Fuseki with ladder breakers (thanks to Min-u Kang).
  • attack_either / defend_both , from comments in engine/reading.c

GNU GO task list, in paragraph Long term issues:

* A much improved combination module.  The combination module of
   today only finds combinations of threats to capture enemy groups.
   A more useful combination module would e.g. find combinations of
   threats to capture a group or enter opponent territory.  It would
   also be strong enough to find combinations of strategic moves and
   more indirect threats (a threat to a threat).  Possibly it could
   combine threats in AND-OR trees (DAGs?) that could be searched
   using ordinary tree search algorithms.  (Revision of combination.c
   is underway.)

And in Ideas:

 * Generalize representation and handling of threats so that we have a
   graph representation of threats that can be searched to see how
   different threats interact.

Attachments

double-ladder-breaker-wins.sgf Download (544 bytes) - added by alain 5 years ago.
move in K9 breaks both ladders, so save one, and win the game
miai-problem-1ply-ahead.sgf Download (231 bytes) - added by alain 5 years ago.
double threat to either capture or make a second eye. Winning move.
GoSeiGen-time-fuseki.sgf Download (613 bytes) - added by alain 5 years ago.
fuseki with ladder, and ladder breaker on opposite corner
hidden-ladder-from-pro-game.sgf Download (1.2 KB) - added by alain 5 years ago.
invisible ladder (but well known)
ladder3.sgf Download (482 bytes) - added by alain 5 years ago.
complicate fight (joseki?) and ladder breaker
attack_either.defend_both.sgf Download (287 bytes) - added by alain 5 years ago.
example from comments in engine/reading.c

Regression Results

Attachment Rev. PASS FAIL Nodes Status

Change History

Changed 5 years ago by alain

move in K9 breaks both ladders, so save one, and win the game

Changed 5 years ago by alain

double threat to either capture or make a second eye. Winning move.

comment:1 follow-up: ↓ 7 Changed 5 years ago by alain

  • Description modified (diff)

comment:2 Changed 5 years ago by alain

  • Description modified (diff)

comment:3 Changed 5 years ago by alain

  • Description modified (diff)

comment:4 Changed 5 years ago by alain

  • Description modified (diff)

Changed 5 years ago by alain

fuseki with ladder, and ladder breaker on opposite corner

Changed 5 years ago by alain

invisible ladder (but well known)

Changed 5 years ago by alain

complicate fight (joseki?) and ladder breaker

comment:5 Changed 5 years ago by alain

  • Description modified (diff)

Changed 5 years ago by alain

example from comments in engine/reading.c

comment:6 Changed 5 years ago by alain

  • Description modified (diff)

comment:7 in reply to: ↑ 1 Changed 5 years ago by nando

About miai-problem-1ply-ahead.sgf, this one can be solved at OWL level.

Something along these lines should be enough:

Pattern DCnn

.OX
XXO
.O*

:8,c, threatens_to_capture(A), value(35)

.CX
AAO
bO*

; olib(b)==1 && oplay_attack(*,A) && !defend(C)

(the olib clause is possibly superfluous)

comment:8 Changed 5 years ago by arend

Alain, could you maybe add regression tests for these examples? (E.g. in strategy5.tst.) Ask if you are unsure how to do this.

comment:9 Changed 3 years ago by gunnar

  • Milestone changed from 3.8 to 3.9.x
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