False Positives

There are four cases for any pair and any investigation:

1. Pair guilty, detection guilty

There is nothing to be concerned about.

2. Pair guilty, detection not guilty

This may happen. It is important to understand some of the reasons:

They stopped cheating

They only cheated for a short time

They were only minimally cheating

There are lots of different detection tests. Just because a pair has a "not cheating" value for one test does not mean they are not cheating. To avoid this situation, multiple different tests are run on the data.

We need to distinguish between two cases:

1. Automated tests generate a list of suspicious pairs.

2. A pair is investigated.

For case 1, where an automated test has highlighted a pair and indicated that they might be cheating, more detailed tests should be run.

If a pair is investigated, and is guilty, but the tests indicate no cheating then this is a concern for the tests. For example, if a pair is only minimally cheating, it is difficult to both detect and also to prove.

So far, I have not had any cases, but some should be expected. This is a mild concern - allowing cheating players to "get away with it". However, this is a much lesser concern than the next scenario.

3. Pair not guilty, detection guilty

This is the biggest concern for players (and administrators).

What can be done to reduce the number of false positives?

There is not a single test for detecting cheating in Bridge. There are multiple tests. If some tests indicate "no cheating", but some tests indicate "cheating" then a more detailed analysis of the boards may be needed.

4. Pair not guilty, detection not guilty

There is nothing to be concerned about.