The National A.A.U. championships began in New Haven yesterday, but for Bruce Hunter--and just about everyone else--the important event won't come until tomorrow, when the trials and finals for the 100-yard freestyle sprint will be held.

The 100-yard freestyle event is traditionally the most interesting, and this year competition promises to be exceptionally keen. Any of half a dozen swimmers, including Hunter, could conceivably break the 48.2-second record set by Jeff Farrell last year.

One of Hunter's competitors will be Lance Larson of Southern California. Larson and Hunter swam the 100-meter event in the 1960 Olympics; Hunter finished fourth, and Larson was declared second in a controversial finish with Australia's John Devitt.

Also entered are Frank Legacki, who set a new NCAA mark in the 50-yard freestyle last week, Ray Padovan, and Steve Jackman. Farrell, last year's winner, is studying abroad this year, so he will not compete.

Saturday will also be the big day for the Crimson's only other entrants. Jeff Lewy and John Shelton, competing in the three-meter dive.

Hunter, Lewy and Shelton will have to pay their own way to New Haven, since it is not a University policy to underwrite participants in A.A.U. track or swimming meets.