We have several computers that are constantly processing data from different Bridge platforms organizations. At the end of each day, one computer generates tables of partnerships with a different minimum number of boards played. We have 150+ different cheating metrics. We use one of these metrics and rank the partnerships in the order that they are most likely to be cheating, or, more specifically, how likely their unusual actions are successful. The tables below contains the ranked list of the partnerships, based on a different minimum number of boards played.

For partnerships where both players have been convicted, we display their BBO names and the number of boards that we have in our database. Note that we do not claim to have all boards, however we have not deliberately removed any boards.

To 'prove' that we already know the names we display a 'secret' field and a 'SHA 256 Hash' field. Best explained with an example:

Rank	Player 1	Player 2	Number of boards	Secret	SHA 256 Hash
1	NHAMMOND1	NHAMMOND2	744	4879f0f9362ef1b2dd1a1ef842da4d0476f7045feb2175d1d15c87e437d838ef	dfe07d815cd7eae959de775c760a304930f9830b146398973c88fbcc3bcb2cce
2	n/a	n/a	n/a	n/a	075fce9f341efdda520752b76f3e6a5347d23305b39e5eff7ff5bedd2adfa7a2

The 'SHA 256 Hash' is generated by calculating the SHA 256 hash for the text [Player_1][Player_2][Secret]. There are many online SHA 256 Hash generators, for example, that you can use to verify. SHA 256 is one of many cryptographical algorithms that generate a "Message Digest" from text.

Entering NHAMMOND1NHAMMOND24879f0f9362ef1b2dd1a1ef842da4d0476f7045feb2175d1d15c87e437d838ef into an online generator will show the result of dfe07d815cd7eae959de775c760a304930f9830b146398973c88fbcc3bcb2cce. Make sure there are no spaces when you enter the text. This verifies that the text generates the published SHA 256 hash.

The second pair is currently not shown as they have not been convicted. When they are convicted, the names and the secret to generate the SHA 256 hash, will be revealed. The second pair is NHAMMOND3 and NHAMMOND4. After they are convicted, then the table will be updated to become:

Rank	Player 1	Player 2	Number of boards	Secret	SHA 256 Hash
1	NHAMMOND1	NHAMMOND2	744	4879f0f9362ef1b2dd1a1ef842da4d0476f7045feb2175d1d15c87e437d838ef	dfe07d815cd7eae959de775c760a304930f9830b146398973c88fbcc3bcb2cce
2	NHAMMOND3	NHAMMOND4	696	33ea9591f7832beaf2dd60823453ce06a12be3e6bdcbcf9ce6b91662369ae671	075fce9f341efdda520752b76f3e6a5347d23305b39e5eff7ff5bedd2adfa7a2

We verify the hash by entering NHAMMOND3NHAMMOND433ea9591f7832beaf2dd60823453ce06a12be3e6bdcbcf9ce6b91662369ae671 into and confirm that the result is 075fce9f341efdda520752b76f3e6a5347d23305b39e5eff7ff5bedd2adfa7a2.

The mathematics of SHA 256 hashes is that it is considered impossible to reverse engineer a SHA 256 hash. It is considered mathematically impossible to extract the pair's names from the published 'SHA 256 hash'. Authorized customers of Hammond Software have access to the secret, full names, and also a report on the pair.

The tables can be large. To speed up display, and to quickly go to a particular number of boards, the tables are displayed "hidden". You must click on the "Show/Hide" button to fisplay them.

The cheating threshold has been set quite high. Almost certainly there are cheating players who are below this threshold.

This data is based on BBO events. We do not claim to have all boards. The 'cheating threshold' has been determined by volunteers and manually analysis of cheating players.

You will see many reporting cheating pairs that are below the threshold that we use. The threshold for cheating is subjective; we use a very high threshold for this work.

The amount of data is potentially very big. We display in tables of rows of approximately 500 as some browsers struggle with large tables. We stop displaying data approximately 100 pairs after the last cheating pair.

Probably. Some National Bridge Organizations (NBOs) do not release the information, or we have yet to process the information from that NBO. Let us know and we will look at adding.

We do track some larger clubs. We do not typically publish these results on the public side.

Contact us. We do provided the unencrypted names to our customers along with the reports.

The number of boards is updated every day. Probably once a month we update the last of convicted cheating partnerships as this is mostly a manual effort so there is typically some delay in reporting.

A red row indicates a cheating pair or a suspected cheating pair. All pairs above our cheating threshold are marked in red. All convicted cheating pairs are also marked in red.

There are various possible reasons.

It can be difficult to know which partnerships were cheating. For ACBL, we use the Members Under Discipline (MUD) list. The MUD does not list the partnerships, just the players. We mark all players that are convicted (or resigned). For example, if players A and B were convicted in a partnership, and also players C and D then all boards with any of these players are marked. If players A and D were also in a partnership, but were NOT cheating, then their data will be shown as both are convicted players.

Another reason is that partnerships cheat in different ways. We have multiple detectors. We only publish the results from a very limited number of these detectors. An example would be Fantoni/Nunes. They were not cheating for the opening lead, but were cheating with the opening lead. A detector for opening leads would show that they ranked about average for top players. This is also true for some of the cheating players.

Yes! Change the URL from nbos1 to nbos2 to see a completely different metric with its own cheating threshold.

Send us an email and we will either reply or look at adding the question.