We were presented three Codenames boards with exceptionally high-scoring plays. A natural first step is to find the correct cards grouped by each clue, these words are

Clothing 9: POLO DRESS TUXEDO SHOE SHORTS BOOT CAP GLOVE SUIT

Animal 11: DUCK SCORPION OCTOPUS CUCKOO PENGUIN RABBIT SHARK DOG TURTLE REINDEER EAGLE

Food 9: SOUP CHEESE POTATO PIE SALAD CARROT PIZZA HAMBURGER BISCUIT

Then, using some flavor clues, you may notice that you can convert each row into a binary number (where a selected word is represented by 1 and an unselected word represented by 0) between 0 and 31, which can conveniently be converted to a letter with the standard 1=A, 2=B, 3=C cipher. For example, the first row of

POLO ENGLAND SKYSCRAPER DRESS TUXEDO

has POLO, DRESS, and TUXEDO selected, and ENGLAND and SKYSCRAPER unselected, so would convert to the binary number 10011, or 19 in decimal, which converts to ‘S’.

Reading these rows down the puzzle you get SCRABBLESUMODD_ (the final row gives 00000 which doesn’t convert to a letter). We can read this as “Scrabble sum odd,” a new property we can use to select and unselect words on the board (the flavor text also suggests recursively looking at the board over and over). So we go about the same procedure but now select words with odd scrabble sum. For example, in the first row, the scrabble sums are 6, 9, 21, 6, and 14, so the binary digits we get for which of these are odd are 01100, which is 12 in decimal, giving an ‘L’.

Reading these rows down the puzzle gives LONGERTHANFIVE_ (again the final row gives 00000), and we have yet another condition for words having more than five letters. Recurring yet again, (now the first row gives 01101=13=’M’), we read off MIDDLELETTEROF_

Now we don’t have an obvious condition, but the final row failing to match any of the previous clues is starting to stick out. All of the words in this final row are odd in length, and thus have a well defined middle letter, which read from left to right SIEVE, the somewhat appropriate answer to the puzzle!

Congrats to the solvers that successfully navigated the series of clues!