The whole idea behind yacht racing is that the human beings aboard, not the boats, are supposed to determine which boat crosses the finish line first. Ideally, the boats involved, especially in what is called one-design racing, are exactly equal in length, width, weight, sail area and many other measurements. The only variables are supposed to be the skippers and the crew.

The trouble with yacht racing is that it never, ever, works out that way. No two boats are ever equal. On the starting line there is always someone with a set of sails that are just a little bit better cut, someone with a hull that has fewer bumps or imperfections, someone with a mast that bends perfectly in a gust, and maybe, just maybe, someone with a keel that has little wings on it.

When the Australians showed up at Newport two years ago with their latest 12-meter challenge for the America's Cup, they were the someones with the now-famous winged keel. And if it had been just another yacht race, not a contest stretching back to 1851 in which nation after nation had pitted millions of dollars and manpower toward removing a strong symbol of national pride from its perch at the New York Yacht Club, the winged keel would have been seen as just another piece of new exotica trying to make yet another yacht a second or so faster per mile than the competition. It wasn't too long ago that the first Kevlar sails showed up at a starting line, or that carbon fibers were used to reinforce a mast.

The winged keel -- kept covered throughout the Newport, R.I., races by a shroud to heighten mystique and frighten the Americans -- seemed to change the contest into one that would match a person against a boat. To many in the yachting world the 1983 America's Cup would not be a matter of whether Dennis Conner, the skipper of Liberty, was a better sailor than the Australia II's John Bertrand, but whether Conner was so much better than Bertrand that he could take an inferior boat and win anyway. In this book, Bertrand calls the scenario "Superboat vs. Super Helmsman."

Interestingly, what Conner tried to do can be done. A terrific skipper can take a seemingly uncompetitive boat and bring it across the finish line several boat lengths ahead of a less-skilled skipper sailing the finest boat in the fleet. But in the America's Cup, everyone is terrific to start with, the very best from a nation's pool of sailors, and the room to be marginally better than another skipper is narrow indeed. The room for one crew to be marginally better than another is also narrow.

For the America's Cup, boats are not exactly one-design. They are designed to a formula that allows for quite a bit of fiddling but insists that the boats come out quite similar to each other. A designer can increase sail area -- the engine of a racing yacht -- but might have to decrease the overall length of the boat or make some other adjustment in the design so that when all the measurements are plugged into a formula, the final number is right.

Previous efforts at breakthrough designs for America's Cup boats have largely been failures. Bertrand himself, in setting his mind on winning the cup, wanted very much to have a good design that was not radical. When Alan Bond, chairman of the Australia II syndicate, first unfurled plans for the winged keel, Bertrand writes that he "nearly flipped. After all that I had told him -- no gambles, no risks, no trick boats, just put me out there on equal terms -- Benny Australia II designer Ben Lexcen turns up with something that looks like a bloody rocket underneath the cockpit."

However, after reviewing data from winged-keel designs test-towed at the Netherlands Ship Model Basin, Bertrand, an engineer who did graduate work at MIT, agreed the boat should be built. "The tank tests, after all, had said that in 20 knots of breeze we must win by 20 minutes," he writes.

Too bad Bertrand didn't get it the way he wanted -- a 12-meter yacht that could go fast but wasn't so innovative -- because he seems determined to spend his life proving he's number one, a winner on his own terms. And to prove that, he must devote a lot of his book to saying -- having said the boat was very, very fast -- that it wasn't Lexcen's design that won at Newport, but Bertrand's skill, and the skill of his crew. If his appoach to winning had not been so firmly rooted in sports psychology, which he appropriately points out is referred to as "brainwashing" by some, or if this book were not such an exercise in gross egotism, he might be more convincing.

He is certainly convincing when he says that at times he wanted to win the America's Cup more than he wanted to keep his marriage together. He is at times also convincing when he says that he barely beat Conner, that he made absolutely horrid mistakes, and that he has a terrible temper.

Nevertheless, John Bertrand has given us two gifts with this book: First, his second-by-second description of the on-deck fury aboard a racing yacht is spellbinding and insightful for those millions who will surely be caught up in the comeback attempt for the cup; second, his arrogance about the victory will give American competitors exactly the kind of psychological determination that Bertrand would hope never to offer an opponent. Too bad Bertrand has decided not to put his reputation on the starting line again.