A more thorough explanation:

The logical-relationship standard is a test used in civil procedure to determine whether a defendant's counterclaim is compulsory. This test examines whether both claims are based on the same operative facts or whether those facts activate additional rights for the defendant. The main consideration is whether hearing the claims together would promote judicial economy and efficiency.

For example, if a person sues their landlord for breach of contract, and the landlord files a counterclaim for unpaid rent, the logical-relationship standard would consider whether hearing both claims together would be more efficient than hearing them separately. If the court determines that hearing both claims together would promote judicial economy and efficiency, then the counterclaim would be considered compulsory.

The logical-relationship standard is flexible and allows for a case-by-case analysis. It is widely accepted among courts, although it has been criticized for being overly broad and uncertain in application.