At a CASI cookoff each judge gives every cup a single whole number from 1 to 10, weighing five criteria: aroma, red color, consistency, taste and aftertaste. The rulebook forbids pluses, minuses, fractions and decimals. A judge who decides from aroma, color or consistency not to taste a chili must still score it. A judge may not re-taste a chili once it has passed down the table, and must use a new spoon for every taste. Table monitors check each cup for marks and fillers before it is set down, and discussion of the chili is not permitted.
The ICS works by ranking rather than scoring. Judges may begin at any cup, move counter-clockwise and re-taste at their discretion until each has chosen a first, second and third. Scorekeepers award three points for each first-place vote, two for second and one for third. The ICS instructions ask judges to pick the chili they individually like best, and describe what usually does well: an appealing look and aroma, tender meat that is neither mushy nor firm, sauce of balanced thickness with distinct chili flavor, and heat that is neither bland nor too hot. The two bodies also differ on palate cleansers. CASI lists crackers, cheese, celery and grapes and includes beer on its supply checklist; the ICS recommends flour tortillas, sour cream and water and prohibits alcohol in the judging area.
Large fields pass through rounds. CASI sends at least half of each preliminary table forward and renumbers the cups at every level, so that a final table of roughly fourteen to twenty chilis is judged by at least five, and preferably ten, judges who have not tasted chili that day. Final-table ties are broken by drawing judging sheets at random, or by a panel of three fresh judges, which CASI requires for first-place ties at Terlingua. The ICS sends the top five from each preliminary table to a final table lettered F and breaks ties with three new judges, or five for a three-way tie. CASI’s history credits the blind system itself to Dr. Carl Jaks of Texas Lutheran College, first used at Chilympiad; John Raven records that in the earliest cook-offs judges went from cook to cook.