Rule for masculine · der
-or → der · 0.7% (exception: das Tor)
Many nouns of Latin origin ending in -or that name a person or a profession are masculine: der Autor, der Direktor, der Moderator. It only covers 0.7% of frequent words, but the pattern is easy to spot - the plural is usually formed with -oren (Autoren, Direktoren). Watch out, though, for das Tor (gate/goal) and its compound das Gegentor (goal conceded) - they have nothing to do with the Latin profession words and stay neuter, so keep them in mind as separate exceptions.