Understand the failure.
Verify the repair.
Small, reproducible software failures. The broken implementation, the fix that didn’t work, and the one that passed—preserved together.
Explore the cases ↓How results are verified ↗WHAT THE ARCHIVE CONTAINS
100840 executable cases. 20168 are open.
Every case records the implementation that fails, the fix that did not work, and the repair that passed its checks—with recorded outputs and source hashes. This release adds 100840 cases across 20168 failure mechanisms and 254 domains.
The open tier gives you the failure and the unsuccessful fix for one case in every mechanism. The remaining 80672 cases, 5 variants per mechanism, are member-only: the verified repair, its recorded checks, and the full fixture suite are held in the member archive. Read the methodology ↗
A RECORD OF WHAT WENT WRONG
Browse the archive / 100840
Negative komi loses its sign · case 01
Reverse komi of -6.5 is applied as +6.5.
Negative komi loses its sign · case 02
Reverse komi of -6.5 is applied as +6.5.
Negative komi loses its sign · case 03
Reverse komi of -6.5 is applied as +6.5.
Negative komi loses its sign · case 04
Reverse komi of -6.5 is applied as +6.5.
Negative komi loses its sign · case 05
Reverse komi of -6.5 is applied as +6.5.
The half glyph is not recognised · case 01
Komi written as 6½ is rejected.
The half glyph is not recognised · case 02
Komi written as 6½ is rejected.
The half glyph is not recognised · case 03
Komi written as 6½ is rejected.
The half glyph is not recognised · case 04
Komi written as 6½ is rejected.
The half glyph is not recognised · case 05
Komi written as 6½ is rejected.
Arbitrary decimal komi is accepted · case 01
Komi 6.3 is accepted as 6.3 points.
Arbitrary decimal komi is accepted · case 02
Komi 6.3 is accepted as 6.3 points.
Arbitrary decimal komi is accepted · case 03
Komi 6.3 is accepted as 6.3 points.
Arbitrary decimal komi is accepted · case 04
Komi 6.3 is accepted as 6.3 points.
Arbitrary decimal komi is accepted · case 05
Komi 6.3 is accepted as 6.3 points.
A bare half-point komi is rejected · case 01
½ and .5 are rejected as invalid.
A bare half-point komi is rejected · case 02
½ and .5 are rejected as invalid.
A bare half-point komi is rejected · case 03
½ and .5 are rejected as invalid.
A bare half-point komi is rejected · case 04
½ and .5 are rejected as invalid.
A bare half-point komi is rejected · case 05
½ and .5 are rejected as invalid.
Surplus handicap stones are accepted · case 01
Black places more free handicap stones than agreed.
Surplus handicap stones are accepted · case 02
Black places more free handicap stones than agreed.
Surplus handicap stones are accepted · case 03
Black places more free handicap stones than agreed.
Surplus handicap stones are accepted · case 04
Black places more free handicap stones than agreed.
Surplus handicap stones are accepted · case 05
Black places more free handicap stones than agreed.
Stones one line beyond the board are accepted · case 01
A coordinate equal to size passes validation.
Stones one line beyond the board are accepted · case 02
A coordinate equal to size passes validation.
Stones one line beyond the board are accepted · case 03
A coordinate equal to size passes validation.
Stones one line beyond the board are accepted · case 04
A coordinate equal to size passes validation.
Stones one line beyond the board are accepted · case 05
A coordinate equal to size passes validation.
Dead stones are still counted as area for their owner · case 01
A dead group adds its stones to its owner area.
Dead stones are still counted as area for their owner · case 02
A dead group adds its stones to its owner area.
Dead stones are still counted as area for their owner · case 03
A dead group adds its stones to its owner area.
Dead stones are still counted as area for their owner · case 04
A dead group adds its stones to its owner area.
Dead stones are still counted as area for their owner · case 05
A dead group adds its stones to its owner area.
Dead stones are also credited as prisoners under area scoring · case 01
Removing a dead stone gives the capturer an extra point on top of the recovered area.
Dead stones are also credited as prisoners under area scoring · case 02
Removing a dead stone gives the capturer an extra point on top of the recovered area.
Dead stones are also credited as prisoners under area scoring · case 03
Removing a dead stone gives the capturer an extra point on top of the recovered area.
Dead stones are also credited as prisoners under area scoring · case 04
Removing a dead stone gives the capturer an extra point on top of the recovered area.
Dead stones are also credited as prisoners under area scoring · case 05
Removing a dead stone gives the capturer an extra point on top of the recovered area.
Trick winner seat runs past the last seat · case 01
When the leader is late in the rotation the winner is reported as seat 4, 5 or 6.
Trick winner seat runs past the last seat · case 02
When the leader is late in the rotation the winner is reported as seat 4, 5 or 6.
Trick winner seat runs past the last seat · case 03
When the leader is late in the rotation the winner is reported as seat 4, 5 or 6.
Trick winner seat runs past the last seat · case 04
When the leader is late in the rotation the winner is reported as seat 4, 5 or 6.
Trick winner seat runs past the last seat · case 05
When the leader is late in the rotation the winner is reported as seat 4, 5 or 6.
A high off-suit discard wins the trick · case 01
Discarding an ace of another suit steals a trick won by a lower card of the led suit.
A high off-suit discard wins the trick · case 02
Discarding an ace of another suit steals a trick won by a lower card of the led suit.
A high off-suit discard wins the trick · case 03
Discarding an ace of another suit steals a trick won by a lower card of the led suit.
A high off-suit discard wins the trick · case 04
Discarding an ace of another suit steals a trick won by a lower card of the led suit.
A high off-suit discard wins the trick · case 05
Discarding an ace of another suit steals a trick won by a lower card of the led suit.
Trumping a led suit does not win the trick · case 01
A player who ruffs with a small trump loses to the led ace.
Trumping a led suit does not win the trick · case 02
A player who ruffs with a small trump loses to the led ace.
Trumping a led suit does not win the trick · case 03
A player who ruffs with a small trump loses to the led ace.
Trumping a led suit does not win the trick · case 04
A player who ruffs with a small trump loses to the led ace.
Trumping a led suit does not win the trick · case 05
A player who ruffs with a small trump loses to the led ace.
Aces rank low in trick comparison · case 01
A led ace loses to a deuce of the same suit.
Aces rank low in trick comparison · case 02
A led ace loses to a deuce of the same suit.
Aces rank low in trick comparison · case 03
A led ace loses to a deuce of the same suit.
Aces rank low in trick comparison · case 04
A led ace loses to a deuce of the same suit.
Aces rank low in trick comparison · case 05
A led ace loses to a deuce of the same suit.
The two of clubs is forced on every lead · case 01
After the first trick a player holding 2C can only lead it.
The two of clubs is forced on every lead · case 02
After the first trick a player holding 2C can only lead it.
The two of clubs is forced on every lead · case 03
After the first trick a player holding 2C can only lead it.
The two of clubs is forced on every lead · case 04
After the first trick a player holding 2C can only lead it.
The two of clubs is forced on every lead · case 05
After the first trick a player holding 2C can only lead it.
Unbroken-hearts lead restriction also forbids the queen of spades · case 01
A player cannot lead QS before hearts are broken.
Unbroken-hearts lead restriction also forbids the queen of spades · case 02
A player cannot lead QS before hearts are broken.
Unbroken-hearts lead restriction also forbids the queen of spades · case 03
A player cannot lead QS before hearts are broken.
Unbroken-hearts lead restriction also forbids the queen of spades · case 04
A player cannot lead QS before hearts are broken.
Unbroken-hearts lead restriction also forbids the queen of spades · case 05
A player cannot lead QS before hearts are broken.
The queen of spades may be dumped on the first trick · case 01
A void player discards QS into the opening trick.
The queen of spades may be dumped on the first trick · case 02
A void player discards QS into the opening trick.
The queen of spades may be dumped on the first trick · case 03
A void player discards QS into the opening trick.
The queen of spades may be dumped on the first trick · case 04
A void player discards QS into the opening trick.
The queen of spades may be dumped on the first trick · case 05
A void player discards QS into the opening trick.
Players must follow the most recent card instead of the led suit · case 01
After a discard, the next player is forced to follow the discard suit.
Players must follow the most recent card instead of the led suit · case 02
After a discard, the next player is forced to follow the discard suit.
Players must follow the most recent card instead of the led suit · case 03
After a discard, the next player is forced to follow the discard suit.
Players must follow the most recent card instead of the led suit · case 04
After a discard, the next player is forced to follow the discard suit.
Players must follow the most recent card instead of the led suit · case 05
After a discard, the next player is forced to follow the discard suit.
Dealer hits soft 17 under S17 and stands under H17 · case 01
The table rule is applied backwards on soft 17.
Dealer hits soft 17 under S17 and stands under H17 · case 02
The table rule is applied backwards on soft 17.
Dealer hits soft 17 under S17 and stands under H17 · case 03
The table rule is applied backwards on soft 17.
Dealer hits soft 17 under S17 and stands under H17 · case 04
The table rule is applied backwards on soft 17.
Dealer hits soft 17 under S17 and stands under H17 · case 05
The table rule is applied backwards on soft 17.
Dealer draws from the back of the shoe · case 01
Hit cards come from the wrong end of the prepared shoe.
Dealer draws from the back of the shoe · case 02
Hit cards come from the wrong end of the prepared shoe.
Dealer draws from the back of the shoe · case 03
Hit cards come from the wrong end of the prepared shoe.
Dealer draws from the back of the shoe · case 04
Hit cards come from the wrong end of the prepared shoe.
Dealer draws from the back of the shoe · case 05
Hit cards come from the wrong end of the prepared shoe.
Ace plus ten is not valued as 21 for the dealer · case 01
A dealer holding A-T keeps hitting from 11.
Ace plus ten is not valued as 21 for the dealer · case 02
A dealer holding A-T keeps hitting from 11.
Ace plus ten is not valued as 21 for the dealer · case 03
A dealer holding A-T keeps hitting from 11.
Ace plus ten is not valued as 21 for the dealer · case 04
A dealer holding A-T keeps hitting from 11.
Ace plus ten is not valued as 21 for the dealer · case 05
A dealer holding A-T keeps hitting from 11.
Dealer hits hard 17 · case 01
The dealer keeps drawing on 17 and busts more often.
Dealer hits hard 17 · case 02
The dealer keeps drawing on 17 and busts more often.
Dealer hits hard 17 · case 03
The dealer keeps drawing on 17 and busts more often.
Dealer hits hard 17 · case 04
The dealer keeps drawing on 17 and busts more often.
Dealer hits hard 17 · case 05
The dealer keeps drawing on 17 and busts more often.
INSPECTABLE BY DESIGN
Every result has a runnable source.
Runnable implementations with recorded outputs, source hashes, and explicit contracts. Related variants share a failure mechanism and belong together in evaluation splits.
Read the methodology ↗