[skottk]

Either just by having developed their brains in a way that word facts just stick, or by constantly seeking out new word facts because that's what they love doing.

I believe that the gentleman in this case instantly saw the word 'cinematographer' hiding in 'megachiropteran' because his brain is a highly trained anagramming machine, and knew that it wasn't allowed because he knew all of the allowed 15-letter words, just in case he might get the opportunity to play one.

High-level players memorize staggering numbers of words. All 2- and 3- letter words is entry-level. All X-J-Q-Z, all Q-without-U, all words you ending in -MAN, all 70+ 7-letter words of the form SATINE+... top-level players know the 4000 4-letter words, the 5000 5's, and way, way more.

This (https://www.yahoo.com/lifestyle/scrabble-records-highest-sco...) lists cases in which 15-letter words were played by adding prefixes or suffixes to other words.