NATIONAL HARBOR, Md. - After forging his way to the finals, 14-year-old Thomas York of Rochester was finally knocked out of the 90th Scripps National Spelling Bee.

York made it to the seventh round, where he was tripped up by the word Carrara, which is a commune in northern Italy east-southeast of La Spezia, population 65,302.

Thursday morning Mr. York moved on after correctly spelling the word cuneus, which means a convolution of the mesial surface of the occipital lobe of the brain above the calcarine sulcus that forms a part of the visual area.

A number of spellers were eliminated during that round, advancing York to the final 22.

Those eliminated include 6-year-old Edith Fuller of Tulsa, Okla., the bee's youngest-ever speller. Edith was only five when she qualified for the national competition.

The finalists were determined by two rounds of oral competition and their scores on a written spelling and vocabulary test they took Tuesday. The national champion will be crowned Thursday night during a live, prime-time broadcast on ESPN.

This year's contest is operating under a new set of rules designed to prevent it from ending in a tie for the fourth year in a row.

"Some people were saying we think co-champions every year is great, don't change a thing," said Paige Kimble, the bee's director and the national spelling champion in 1981. "We had other people who felt strongly that it was not in the best interest of the program to continue to have co-champions. They were encouraging us to put provisions in our rules to make it impossible to have co-champions."

The bee aimed for middle ground, putting in place new rules that may — or may not — prevent another tie.

All finalists still left standing Thursday evening will be given a tiebreaker written test with 12 words and 12 vocabulary questions. If two or three spellers remain on stage at the end of 25 rounds, the speller with the highest score on the tiebreaker test will be declared the national champion.

If there's a tie on the tiebreaker, the spellers with the highest scores will be declared the winners. Under the new rules, it's possible there could still be two — or even three — national champs. "We all will have to see what happens," Kimble said.

This year's 291 spellers come from all 50 states and the District of Columbia, as well as American Samoa, Guam, Puerto Rico, the U.S. Virgin Islands and the Department of Defense Schools in Europe. Eleven represent the Bahamas, Canada, Ghana, Jamaica, Japan and South Korea.

The winner – or winners – will take home $40,000 in cash, a trophy and other prizes.