KEN JENNINGS is pretty darned smart. By Friday, he had won more than $1 million over 33 straight shows on ''Jeopardy,'' making him the game show's top money winner and longest-lasting champion. And he's still going strong.

You've got to be bright and quick to win at ''Jeopardy.'' You have to know a lot of things. And although the game is not chess in terms of complexity, or even checkers, there do seem to be some elements of strategy.

But while everyone would agree you need smarts, is that the same thing as intelligence? For that matter, what do we really mean by intelligence?

No one knows the answer to either question. Intelligence has preoccupied scientists and philosophers at least since Plato, but so far nobody has been clever enough to come up with a theory that everyone can agree on.

One contender for the title of ''Smart Enough to Say What Smart Actually Means'' is Dr. Howard Gardner, the Hobbs professor of cognition and education at the Harvard Graduate School of Education. His theory of multiple intelligences (at least seven, probably more) is built on the notion that we have been using one word to describe all sorts of abilities -- linguistic, musical, logical-mathematical, spatial, interpersonal and others.

''Jeopardy'' draws on a particular ability, Professor Gardner wrote in an e-mail message. Usually, ''what is being tested here is verbal memory,'' he wrote. ''Have you read a lot (or, perhaps, have you heard a great deal) and can you remember the facts, names, dates, song titles, movie names, etc., that you read or heard about once or twice?''

''It is important to stress that this is verbal linguistic memory,'' he continued. ''We have no idea whether the successful contestant would remember faces, locations of buildings in a city that he/she visited, musical themes, dance steps, how someone felt at a party last week, how she/he felt when 10 years old and no one played with him/her on the playground.''

Dr. Gardner said there were probably other talents, beyond verbal memory and a fast buzzer finger, that are useful in playing ''Jeopardy.''

''I would guess that the successful contestants tend to organize things in their mind around categories,'' he wrote in his e-mail, which is certainly a skill in ''Jeopardy.''

''Such an organized mind suggests either that the person is very logical, or that he/she reads and memorizes works that are already organized.''

In addition to his quick recall, Mr. Jennings has also demonstrated lightning speed at solving anagrams. Perhaps this might be called ''puzzle intelligence.''

Dividing intelligence into many discrete abilities is just one approach, said Jonathan Plucker, a cognitive scientist at Indiana University who runs a Web site describing the various attempts to understand human intelligence ( Other theorists believe that intelligence is a general ability that is translatable from one field to another. There is some evidence, Dr. Plucker said, that really impressive intellectual performance in one area is correlated with success in other areas. A brilliant philosopher, in other words, might also make a great radiologist.

Dr. Plucker said, however, that he thought the question many cognitive scientists were asking was not, ''Is there one vs. many'' kinds of intelligence, but ''What does a theory of many look like?''

He said he was quite impressed after watching Mr. Jennings compete. ''He was playing the other competitors as much as he was playing the board,'' Dr. Plucker said, by making guesses, holding back at certain times, acting confident. ''This guy was clearly good at contextual sorts of intelligence,'' which is to say, reading the situation and the rules, in addition to having the necessary knowledge.

Dr. Gardner also recognizes this kind of skill. For example, he said, ''in poker, bluffing is much more about inter- and intrapersonal intelligence than about logical intelligence.''

Finally, there is something that is apparent to anybody who watches the show. Mr. Jennings is the champion. He is relaxed and confident, like the Yankees playing at home. That doesn't guarantee success, but it makes it a lot tougher for challengers.

''Confidence, or lack of confidence, can really affect how you process information,'' Dr. Plucker said. ''He has a huge emotional advantage.''

Given Mr. Jennings's knowledge, sense of strategy and clear sense that the challengers are coming onto turf that he owns, Dr. Plucker concluded, ''he's going to have to have a terrible day for someone to beat him.''

Dr. Plucker added that he would like to see Mr. Jennings compete against other champions, which would limit his emotional advantage.

Of course, game-show fame has not always been a blessing. Charles Van Doren, one of the best-known winners of the 1950's, made the cover of Time magazine in 1957 because of his success on a television game show called ''Twenty-One.'' Eventually, however, he confessed that his appearances had been fixed. His decision to engage in deception, it turned out, was not a very smart move.

Drawing (Drawing by Ross MacDonald)