FileBot gives you two
Match Mode options that allow you to decide whether you prefer more
opportunistic matching that works for all files regardless how badly they are named
(with a chance of errors) or
strict matching that only works for reasonably well-named files
(but with no chance of errors) and ignore files that cannot be matched accurately.
Opportunistic:
Match Mode: Opportunistic (or -non-strict mode) is the default option and works for most people in most circumstances.
Opportunistic matching means that FileBot will do it's utmost to guess the
best match for each file based on the information available in online databases
(e.g. TheTVDB or TheMovieDB) and assumes that the episode or movie that each file represents actually exists in the online database.

In those rare cases where the filename does not make sense
(e.g. trying to match Firefly 2x01 which does not exist according to TheTVDB) the
"best match" will still be a bad match since there is no correct match in the first place.

Consider switching from
Manual Confirmation to
Automatic Selection if the first option is consistently on point.

Even though
Opportunistic matching works 99.99% of the time, it is
not guaranteed to work at all times in all circumstances, as such manually
checking matches before hitting Rename is highly recommended.

If you find a bad match, just hit the
DELETE key to

remove the selected match from the list.
Strict:
Match Mode: Strict is useful when processing large numbers of files that are already fairly well-named.
Strict matching means that FileBot will do it's utmost to avoid erroneous matches and ignore files where the correct match cannot be guaranteed. Consequently, in
Strict mode there is no user-interaction or any kind of manual selection since files that do not contain enough information
(e.g. movie name without year) are ignored right away.
Strict matching guarantees that each match is correct, so
checking matches before hitting Rename is not necessary.

When processing a large number of files, it's recommended to first use
Strict matching to process all files that can be processed easily without user-interaction, and then in a second pass use
Opportunistic matching only for the remainder of files that require more attention.