The last two finalists warble for the judges on the final night of competition on “American Idol” (7 p.m., Fox). But will the judges pay attention? Or will they be staring at their pink slips? Reports surfaced or, rather, erupted last week that the entire panel was going to be fired. Even Randy (“Yo, yo, yo, dawg”) Jackson quit, and he’s been part of the show since Millard Fillmore was president.

I don’t know enough, or care enough, and haven’t paid sufficient attention to catalog the shortcomings of judges Mariah Carey, Nicki Minaj and Keith Urban. Suffice it to say, they were famous, so they were supposed to drag their fans into the show’s audience. Instead, they seemed to repel the show’s faithful.

These things happen. And not just on television. Anybody who follows baseball knows that owners can buy a boatload of high-paid talent, but they can’t always forge good teams. It’s called bad chemistry. The latest example of a chemistry project gone awry can be found in Toronto. More than any other team, the Blue Jays added lots of talent in the offseason. Many prognosticators picked them to dominate their division. So far, they stink. It’s only May, so the Blue Jays can turn it around. But “Idol” wraps up its year tomorrow night, and sadly, more people will tune in to see how ugly it gets rather than watch the new winner be crowned. That’s what happens when you turn what was once the most popular talent competition on television into “Hollywood Squares.”

• “Arrow” (7 p.m., CW), a bona fide hit for its network and one of the more successful new shows to launch this season, wraps up its first year with Oliver and Diggle racing to stop the Dark Archer.

Tonight’s season finales:

• A journalist gets embedded with the team on “CSI” (9 p.m., CBS).

• Hellzapoppin’ on “Supernatural” (8 p.m., CW).

Tonight’s other highlights:

• “MythBusters” (8 p.m., Discovery) tackles life’s most compelling question: electric hand dryer or paper towel?

• Auditions continue on “So You Think You Can Dance” (8 p.m., Fox).

• An RV vacation feels too close for comfort on “Modern Family” (8 p.m., ABC).