Have I been asleep for the past three years? I seem to remember the first “Amazing Race,” but how did we get to “Amazing Race 4” (7 p.m., CBS)? Seriously, these shows are proliferating faster than “Chucky” movies.

For the uninitiated, “Race” pits 12 teams of two in a globetrotting game of capture-the-flag. In the premiere episode, the teams have to drive through L.A. traffic in SUVs; find the airport; catch a flight to Milan, Italy; scrounge for hidden bus tickets in a public square; travel to a ski-resort village; climb to the top of a mountain; hang from wires strung hundreds of feet above the Alps; and slog through the snow. The last couple to reach their pit stop is eliminated.

Jon and Al win the “odd couple” prize in this round. They’re best friends who just happen to work as circus clowns. Jon is a human cannonball. Al toils as a clown for a cruise ship line. Yikes! Being stuck on a ship with clowns — now that’s scary. But I digress. Other couples include Tian and Jaree, friends and supermodel wannabes from Florida. If you listen closely, you can hear America rooting for these Amazon brats to lose.

Millie and Chuck seem like an unremarkable couple, but we are continually reminded that they have been dating for 12 years but remain virgins. Just in case we forget, the words “Dating/Virgins” run along the bottom of the screen.

Unfortunately, the 90-minute season debut opens with a frantic pace that hardly allows any of these quirky personalities to emerge. The nonstop scrambling and loud, incessantly pounding soundtrack may give some viewers an amazing headache.

• Dave Attell will open the fourth season of “Insomniac” (9 p.m., Comedy Central) with an hourlong crawl through the pubs, smoke shops, vice districts, art galleries and museums of Amsterdam. He even visits a wooden-shoe factory that shows how the quaint footwear is fashioned “from logs to clogs.”

Tonight’s other highlights

• Amateur acts perform quickly on “30 Seconds to Fame” (7:30 p.m., Fox).
• Grissom shows unusual interest in a kinky murder suspect on “CSI” (8:30 p.m., CBS).
• Shepard Smith sponsors the “news” magazine “The Pulse” (8 p.m., Fox).
• “Frontline/World” (8:30 p.m., PBS) looks at the aftermath of war in Iraq and Vietnam.

Series notes

On back-to-back episodes of “Friends” (NBC), proposal confusion (7 p.m.), Joey apologizes (7:30 p.m.) … The title says it all on “Stupid Behavior Caught on Tape” (7 p.m., Fox) … Wrestling on “WWE SmackDown!” (7 p.m., UPN) … True love on “Sabrina the Teenage Witch” (7 p.m., WB.)

Late night

Hugh Jackman and Kelly Clarkson appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno welcomes Jerry Seinfeld and Third Eye Blind on “The Tonight Show” (10:35 p.m., NBC). Robin Williams appears on “Late Night with Conan O’Brien” (11:35 p.m.) … Julia Louis-Dreyfus, Hugo Weaving and Switchfoot are booked on “The Late, Late Show with Craig Kilborn” (11:37 p.m., CBS).