The best show that thoroughbred racing has offered in many a moon continues today when Affirmed and Alydar renew their unmatched rivalry in the $104,800 Travers Stakes.

This lovely resort community is located at the base of the Adirondacks, once the heartland of the Iroquois nation. A (no longer birch-bark) canoe, traditionally painted in the colors of the previous year's Traver winner, drifts in the Saratoga infield lake. Today, given a break in the weather, the crowd will spill over into that infield, in record numbers, as a backdrop for the nationally televised (Post time 5:36 on WDVM-TV-9) event.

Ordinarily, when one horse defeats another horse as regularly as Affirmed has Alydar this season, it would be difficult to generate much enthusiasm for another of their races. The Travers, known as the "Midsummer Derby," is Act No. 10 in theirlong running production, and the facts are these:

Affirmed holds a 7-to-2 edge over Alydar, is eight for eight overall this year, and has earned a place in history as America's 11th Triple Crown victor.

Affirmed has an opportunity this afternoon to erase Secretariat's single season high of $860,404 in earnings.

Affirmed is about to be syndicated for a record $15 million, or $3 million more than was paid for the future stud services of Seattle Slew.

A fan needs a pretty good memory to recall when Alydar last beat Affirmed, in the Champagne Mile at Belmont Park, Oct. 15. Yet Alydar keeps coming on, his supporters refusing to believe their hero cannot overtake Affirmed, if given a better field of competitors.

Affirmed downed Alydar by 1 1/2 lengths in the Kentucky Derby, by a neck in the Preakness, and by a head in the Belmont Stakes. Each time the margin of finish has been close, Affirmed has won. The chestnut son of Exclusive Native even fought back, after losing the lead in the stretch, to outgain the Calumet colt in the Belmont.

"Some people," said a slightly perplexed Laz Barrera, Affirmed's trainer, "take an awful lot of convincing. They should have seen all they needed to see last fall, in the Laurel Futurity, when Affirmed beat Alydar by a neck."

John Veitch, trainer of Alydar, is one of those who Affirmed still must convince. "I'm looking for the Belmont, again, except with a different outcome," the young conditioner said yesterday. "Alydar has improved since then. He is more mature, more settled. The best part is that he has retained his enthusiasm for racing. You don't want them to go sour. His last two races, since the Triple Crown, were perhaps his best."

Alydar scored by 13 lengths in the Arlington Classic in Chicago July 22, the embarrassed a good group of older horses that included J. O. Tobin in the Whitney Stakes here two weeks ago, winnig by 10 lengths.

Affirmed did not return to action until Aug.8, but his return was sensational, rallying from nearly 10 lengths back to catch the speedy Sensitive Prince by a length at the end of nine furlongs.

Steve Cauthen is Affirmed's regularly rider. But the brillant 18-year-old jockey suffered shoulder and knee injuries in a spill here last week and does not feel up to so important an assignment. He will be replaced by Laffit Pincay, who piloted Affirmed to victory in the Hollywood Juvenile last summer and in the Santa Anita Derby last winter.

Should Alydar and jockey Jorge Velasquez turn the tables on the favorite in the Travers, the loser's "excuse" would be obvious. Pincay is on the hot seat in an impossible position where he is supposed to win, and a defeat would be his fault, not Affirmed's.

Affirmed rarely has needed an excuse. He has made his own racing luck, much more often than not, and his repeated success over Alydar in their prolonged, pulsating stretch duels this year are testament to which of the two is (or at least was) the superior 3-year-old.

Vietch makes two interesting points however.First, thoroughbreds do continue to grow and mature at 3. Alydar, a chestnut sun of Raise A Native, is bigger and stronger and certainly was gawkier than Affirmed this spring. Alydar may not yet have reached his peak, while Affirmed could have arrived there three months ago.

Secondly, Veitch is correct when he notes how makeup of the Preakness and the Belmont fields tended to improve Affirmed's chances of winning while working against Alydar's. Those two were "match" races in which speedier, shiftier, more versatile Affirmed enjoyed a great advantage, tactically, over Alydar's strong finish.

The Calumet trainer has benn praying for some quality early speed to appear in these races, such as Sensitive Prince. The only time that colt did compete against Alydar and Affirmed in the Kentucky Derby, Alydar failed to fire.

"The presence of Sensitive Prince can change things," Veitch said Wednesday of the Travers. "Affirmed cannot permit him to steal off and build a lead, like he did in the Jim Dandy. If Affirmed has to put pressure on sensitive Prince, that could cost him something when Alydar comes to him."

That was Wednesday. Unfortunately for Veitch, the name of Sensitive Prince was not among the four entered Thursday for the Travers. Nasty And Bold and Shake Shake Shake complete the lineup, all four 3-year-olds carrying 126 pounds over the 1 1/4 miles.

This means the task of "pushin" Affirmed is, once again up to Alydar. A replay of the 1962 Travers, when Jaipur and Ridan hooked up in a wire-to-wire duel, might be in store.

Should this Travers be that close, the logical pick is Affirmed. Affirmed has Alydar's number. Both are outstanding colts. Never have there been two 3-year-olds of such quality to appear in the same season. But the bottom line thus far shows that Affirmed hasthe greater desire to win and that is what the breeding and racing of the thoroughbred horse is all about.