Simon Cowell is starting all over again.

Past seasons of "American Idol" don't necessarily factor in when the famously snarky British recording executive and his cohorts in judging, Paula Abdul and Randy Jackson, start gauging another crop of pop-star wannabes. The fourth season of the hugely popular Fox talent contest begins with a two-hour episode at 8 p.m. Tuesday on Channel 9 with Ryan Seacrest also back as the host of weekly editions again airing at 8 p.m. each Tuesday and Wednesday.

Holding to "Idol" tradition, the new season opens with highlights of auditions Cowell, Abdul and Jackson endured in their quest to find finalists for the competition. Cleveland; New Orleans; Las Vegas; Orlando, Fla.; San Francisco; St. Louis; and Washington, D.C. were the tryout cities that ultimately could yield another "Idol" winner like Kelly Clarkson, Ruben Studdard or Fantasia Barrino.

However, last year's edition also produced William Hung ... who gained fame simply by butchering any tune he could wrap his vocal cords around, starting with Ricky Martin's "She Bangs."

"We've had what we call 'the Hung Effect' this time," Cowell reports. "There's no question we've had people showing up and singing badly on purpose. They may as well have neon signs on their foreheads. That whole thing came down to one word, 'naivete.' Even at the point where (Hung) got a recording contract and was talking about doing a second album, I told him, 'There will be no second album.' That sort of delusion was part of his charm."

For better or worse, each phase of "American Idol" still seems fresh to Cowell.

"The good thing is that because it's a reality show, it's not scripted. Because you have a new group of people showing up (to try out), it does sort of feel like a new show each time. Having me and Paula and Randy and Ryan around gives it consistency, but it's always new faces otherwise, so you have to approach it like it's the very first show."

Even after three seasons, Cowell hesitates to get too specific on what's sought in an "American Idol." He reasons, "What you can do is look back and think, 'What was the best year? And why?' Without question, the best 'American Idol' year for me was the second one. It resulted in the best final we've ever had, with two people (Studdard and Clay Aiken) who never would have been given a shot in the music industry under normal circumstances. The lessons really are 'Don't get too smart' and 'Let the public choose the talent for you.' Then you'll get it right.

"We genuinely didn't know who was going to win that one," Cowell adds, "whereas in the first and third seasons, it was quite obvious. Until the moment the result was read - and I was convinced from the previous episode that it was going to be the other way around - it was exciting for all of us. I hope we can get back to where we were then, because that was just a great season."

Among "Idol" changes this year: an increase in the cutoff age for contestants, from 24 to 28; a tightening of the semifinal round, from five weeks to three, with 24 finalists selected instead of the previous 32; the addition of music stars such as Kenny Loggins and LL Cool J to gauge auditions; and the expected absence of celebrity guests when it comes to the actual judging.

Cowell never seems at a loss for unique critiques or outright put-downs of music hopefuls who don't make the grade for him.

"They make it easy. The only way you can do this is to go in without any preconceived ideas at all as to what you'll do or say. Luckily, we have the luxury on this show of being able to say exactly what we're thinking as the audition is happening."

Some of those who audition are more than ready for that, going on the attack before Cowell can.

"The funny thing," he notes, "is that this is such a true reality show; no matter what you plan to say or do, every person who enters that room knows the next two to three minutes could dictate the rest of their lives. Everything that's preplanned disappears. Most of the aggression comes from the fact that they simply want to get through the audition successfully, and when I say 'No,' they just go nuts. That's good, though. That's the way it should be."

If that sounds mean, Cowell doesn't intend it to be.

"If people expect you to be unpleasant just for the sake of it, you become a caricature," he reasons. "What we're trying to do is to give a sense of realism and honesty to the people who show up, and I can do that from the years I've had in the music industry. I think what people expect from us now is the truth, rather than just a controversial sound bite. We've got a very sophisticated viewing audience, and they don't want to feel cheated."

In that vein, a furor erupted last season over accusations the phone system for "American Idol" voting was rigged.

"The fact is, this is the fairest system we could possibly put in place," Cowell maintains. "We're allowing the audience to pick the finalists for us. If you don't phone in enough for the person you like, he or she will be kicked off. You can't be more fair than that. I promise you, if I felt the show was being manipulated, I wouldn't stay on - but I love the controversy. It's what I look forward to each year."