QQ - How do I select the "best" record according to some numeric score?

Use HighDiscrete to select the record with the highest score.   

See DataSet HotBar - Quick Reference (Function | High Discrete) for details.

Note that this method requires a key table - the key table is the PRIMARY table in a PRIMARY -< FOREIGN  (ONE to MANY) relationship.    For example, to select the record with the highest transaction id for each customer, a transaction (sales) table and customer (individual) table is required:

A key table can be created using any of the following methods:

• CreateKeyTable method, 
• Database tree | Right-click | Advanced | Make Key Table
• Engineering | Make Key Table