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
Matching rank without suit is refused · case 01
A seven cannot be played on a seven of another suit.
Matching rank without suit is refused · case 02
A seven cannot be played on a seven of another suit.
Matching rank without suit is refused · case 03
A seven cannot be played on a seven of another suit.
Matching rank without suit is refused · case 04
A seven cannot be played on a seven of another suit.
Matching rank without suit is refused · case 05
A seven cannot be played on a seven of another suit.
An eight cannot be played on a declared suit · case 01
After a declared suit, eights of other suits are refused.
An eight cannot be played on a declared suit · case 02
After a declared suit, eights of other suits are refused.
An eight cannot be played on a declared suit · case 03
After a declared suit, eights of other suits are refused.
An eight cannot be played on a declared suit · case 04
After a declared suit, eights of other suits are refused.
An eight cannot be played on a declared suit · case 05
After a declared suit, eights of other suits are refused.
Reverse in a two-player game hands the turn to the opponent · case 01
With two players a reverse does not let the player go again.
Reverse in a two-player game hands the turn to the opponent · case 02
With two players a reverse does not let the player go again.
Reverse in a two-player game hands the turn to the opponent · case 03
With two players a reverse does not let the player go again.
Reverse in a two-player game hands the turn to the opponent · case 04
With two players a reverse does not let the player go again.
Reverse in a two-player game hands the turn to the opponent · case 05
With two players a reverse does not let the player go again.
Reverse moves play in the old direction first · case 01
After a reverse the next player is the one in the old direction.
Reverse moves play in the old direction first · case 02
After a reverse the next player is the one in the old direction.
Reverse moves play in the old direction first · case 03
After a reverse the next player is the one in the old direction.
Reverse moves play in the old direction first · case 04
After a reverse the next player is the one in the old direction.
Reverse moves play in the old direction first · case 05
After a reverse the next player is the one in the old direction.
Draw cards always hit the clockwise neighbour · case 01
In counter-clockwise play the wrong player draws.
Draw cards always hit the clockwise neighbour · case 02
In counter-clockwise play the wrong player draws.
Draw cards always hit the clockwise neighbour · case 03
In counter-clockwise play the wrong player draws.
Draw cards always hit the clockwise neighbour · case 04
In counter-clockwise play the wrong player draws.
Draw cards always hit the clockwise neighbour · case 05
In counter-clockwise play the wrong player draws.
The draw victim still takes a turn · case 01
After a draw two the victim plays immediately.
The draw victim still takes a turn · case 02
After a draw two the victim plays immediately.
The draw victim still takes a turn · case 03
After a draw two the victim plays immediately.
The draw victim still takes a turn · case 04
After a draw two the victim plays immediately.
The draw victim still takes a turn · case 05
After a draw two the victim plays immediately.
Court cards count their rank number toward fifteen · case 01
J-5, Q-5 and K-5 no longer make fifteen.
Court cards count their rank number toward fifteen · case 02
J-5, Q-5 and K-5 no longer make fifteen.
Court cards count their rank number toward fifteen · case 03
J-5, Q-5 and K-5 no longer make fifteen.
Court cards count their rank number toward fifteen · case 04
J-5, Q-5 and K-5 no longer make fifteen.
Court cards count their rank number toward fifteen · case 05
J-5, Q-5 and K-5 no longer make fifteen.
Five-card fifteens are not counted · case 01
A hand whose five cards together total 15 misses 2 points.
Five-card fifteens are not counted · case 02
A hand whose five cards together total 15 misses 2 points.
Five-card fifteens are not counted · case 03
A hand whose five cards together total 15 misses 2 points.
Five-card fifteens are not counted · case 04
A hand whose five cards together total 15 misses 2 points.
Five-card fifteens are not counted · case 05
A hand whose five cards together total 15 misses 2 points.
Sub-runs inside a longer run are also scored · case 01
A four-card run also scores its two three-card sub-runs.
Sub-runs inside a longer run are also scored · case 02
A four-card run also scores its two three-card sub-runs.
Sub-runs inside a longer run are also scored · case 03
A four-card run also scores its two three-card sub-runs.
Sub-runs inside a longer run are also scored · case 04
A four-card run also scores its two three-card sub-runs.
Sub-runs inside a longer run are also scored · case 05
A four-card run also scores its two three-card sub-runs.
The crib scores a four-card flush · case 01
A crib whose four cards share a suit but not the starter scores 4.
The crib scores a four-card flush · case 02
A crib whose four cards share a suit but not the starter scores 4.
The crib scores a four-card flush · case 03
A crib whose four cards share a suit but not the starter scores 4.
The crib scores a four-card flush · case 04
A crib whose four cards share a suit but not the starter scores 4.
The crib scores a four-card flush · case 05
A crib whose four cards share a suit but not the starter scores 4.
A jack turned as starter scores nobs · case 01
The starter jack matches its own suit and adds a point to every hand.
A jack turned as starter scores nobs · case 02
The starter jack matches its own suit and adds a point to every hand.
A jack turned as starter scores nobs · case 03
The starter jack matches its own suit and adds a point to every hand.
A jack turned as starter scores nobs · case 04
The starter jack matches its own suit and adds a point to every hand.
A jack turned as starter scores nobs · case 05
The starter jack matches its own suit and adds a point to every hand.
Three of a kind scores as a single pair · case 01
A pair royal is worth 2 instead of 6.
Three of a kind scores as a single pair · case 02
A pair royal is worth 2 instead of 6.
Three of a kind scores as a single pair · case 03
A pair royal is worth 2 instead of 6.
Three of a kind scores as a single pair · case 04
A pair royal is worth 2 instead of 6.
Three of a kind scores as a single pair · case 05
A pair royal is worth 2 instead of 6.
Non-adjacent equal ranks score as pegging pairs · case 01
A five played after 5-6 pegs a pair.
Non-adjacent equal ranks score as pegging pairs · case 02
A five played after 5-6 pegs a pair.
Non-adjacent equal ranks score as pegging pairs · case 03
A five played after 5-6 pegs a pair.
Non-adjacent equal ranks score as pegging pairs · case 04
A five played after 5-6 pegs a pair.
Non-adjacent equal ranks score as pegging pairs · case 05
A five played after 5-6 pegs a pair.
Pegging runs score only three · case 01
Completing a four- or five-card run pegs 3.
Pegging runs score only three · case 02
Completing a four- or five-card run pegs 3.
Pegging runs score only three · case 03
Completing a four- or five-card run pegs 3.
Pegging runs score only three · case 04
Completing a four- or five-card run pegs 3.
Pegging runs score only three · case 05
Completing a four- or five-card run pegs 3.
Reaching exactly 31 is illegal · case 01
Cards that make exactly 31 are refused.
Reaching exactly 31 is illegal · case 02
Cards that make exactly 31 are refused.
Reaching exactly 31 is illegal · case 03
Cards that make exactly 31 are refused.
Reaching exactly 31 is illegal · case 04
Cards that make exactly 31 are refused.
Reaching exactly 31 is illegal · case 05
Cards that make exactly 31 are refused.
Thirty also pegs as fifteen · case 01
Reaching 30 scores 2.
Thirty also pegs as fifteen · case 02
Reaching 30 scores 2.
Thirty also pegs as fifteen · case 03
Reaching 30 scores 2.
Thirty also pegs as fifteen · case 04
Reaching 30 scores 2.
Thirty also pegs as fifteen · case 05
Reaching 30 scores 2.
Notrump contracts miss the first-trick premium · case 01
3NT made scores as a partscore.
Notrump contracts miss the first-trick premium · case 02
3NT made scores as a partscore.
Notrump contracts miss the first-trick premium · case 03
3NT made scores as a partscore.
Notrump contracts miss the first-trick premium · case 04
3NT made scores as a partscore.
Notrump contracts miss the first-trick premium · case 05
3NT made scores as a partscore.
Doubled partscores are not promoted to game · case 01
2H doubled and made gets a partscore bonus.
Doubled partscores are not promoted to game · case 02
2H doubled and made gets a partscore bonus.
Doubled partscores are not promoted to game · case 03
2H doubled and made gets a partscore bonus.
Doubled partscores are not promoted to game · case 04
2H doubled and made gets a partscore bonus.
Doubled partscores are not promoted to game · case 05
2H doubled and made gets a partscore bonus.
Fourth and later doubled undertricks cost 200 non-vulnerable · case 01
Big sacrifices are undercharged.
Fourth and later doubled undertricks cost 200 non-vulnerable · case 02
Big sacrifices are undercharged.
Fourth and later doubled undertricks cost 200 non-vulnerable · case 03
Big sacrifices are undercharged.
Fourth and later doubled undertricks cost 200 non-vulnerable · case 04
Big sacrifices are undercharged.
Fourth and later doubled undertricks cost 200 non-vulnerable · case 05
Big sacrifices are undercharged.
Redoubled overtricks score as doubled · case 01
Each redoubled overtrick earns 100/200 instead of 200/400.
Redoubled overtricks score as doubled · case 02
Each redoubled overtrick earns 100/200 instead of 200/400.
Redoubled overtricks score as doubled · case 03
Each redoubled overtrick earns 100/200 instead of 200/400.
Redoubled overtricks score as doubled · case 04
Each redoubled overtrick earns 100/200 instead of 200/400.
Redoubled overtricks score as doubled · case 05
Each redoubled overtrick earns 100/200 instead of 200/400.
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 ↗