In the most memorable moment of the press tour panel for CBS' "The Crazy Ones" — Robin Williams' first regular series role since "Mork & Mindy" ended in 1982 — Williams responded to a question about whether he's a sad clown by throwing a mock, tear-filled tantrum that ended with co-star Sarah Michelle Gellar literally pulling him back to his seat with his microphone cord. When he finally sat down, he made a few Anthony Weiner jokes ("Do you think he has a thing on his phone that says, 'No more!'?"), then gave a more serious answer about where his comedy comes from.

It was a funny bit during a half-hour when the TCA was a pretty tough room for Williams — at one point, he bombed with a riff on Apple products he'd like to invent, then said, "See, this is good, because you realize, 'This didn't work at all!'" — but also one that wound up illustrating a point Williams and others had been trying to make for the whole panel: that Williams can improvise and do funny voices and clown around, but when the moment calls for it, he can also play a character (in this case, a Chicago ad executive), can read the dialogue as written by "Crazy Ones" creator David E. Kelley, and set up his co-stars Sarah Michelle Gellar and James Wolk to look good.

"We do both," Kelley explained, when asked how much of the show is scripted and how much is improvised. "He says my words perfectly. Then he uses his. We started shooting, he's pretty much word perfect. This is the first time I've worked with him. It sounds like he very much likes the box, he manages inside the box, gets the box down, and then we give him a few takes where he gets to break out of it."

"The bottom line is he writes great stuff," Williams said, "And it's a great base and I have great people to play off of."

Kelley, the Emmy-winning creator of "The Practice," "Picket Fences" and "Chicago Hope," among many others, admitted that working with a comic like Williams made him feel "like I'd been handed the keys to a car I was ill-equipped to drive," which is why he recruited "Modern Family" veteran Jason Winer, who has an extensive background with comedy and improv, to do the show with him.

"We've talked a lot about this show being partially improvised, but the truth is the improvisation is the icing and not the cake," Winer said. "This stuff has substance, both emotionally and personally. The moments of improvisation are really targeted. There are scenes we attack as written. People forget that Robin is a Julliard-trained, Oscar-winning actor... In the pilot, he approached scenes really diligently. His number one goal is to make his scene partner look good. Sometimes, he has to be coaxed to do the thing that we're used to him doing."

"I can be intimidating to work with a comic at that level," Gellar said, while agreeing that Williams often "cares more about making everyone else's stuff work."

"That's the joy of working with a group of people like this," Williams said. "It's partly the training, but acting is a mutual sport. There are moments of solo, but working with others is what makes it interesting. Even with 'Mork & Mindy,' Pam (Dawber) held the line for me. She was incredible, which allowed me to be as outrageous as I was."

And the mutual admiration society set up one of his co-stars to get a laugh. Wolk — playing yet another advertising executive after his "Mad Men" stint as Bob Benson — was also asked what it's like working with Williams, and joked, "Robin is incredibly generous. Things like, 'Don't step on my line, kid,' that's just part of the love."