Leno boosts his late-night lead

In a TV season when NBC is starved for good news at night, Jay Leno is providing some.

His “Tonight Show” has widened its lead over chief rival David Letterman, a noteworthy achievement given CBS’ prime-time dominance and NBC’s fading fortunes. The typical “Tonight” audience has increased by 4% this year to 5.6 million viewers. “Late Show” is down 5%, says Nielsen Media Research.

NBC believes Leno has more nimbly responded to the changing late-night landscape, where viewers have many choices.

Leno has won consistently for a decade, but during that time Letterman’s camp has claimed it wasn’t a fair fight. For years, NBC was the stronger prime-time network, and CBS said that meant more-passive viewers kept sets tuned to NBC. CBS’ temporary loss of pro football during the 1990s also meant fewer opportunities to promote Letterman to young men.

To NBC executives, those always smelled more like excuses than explanations.

CBS said it’s too early to draw conclusions, that this year’s numbers are skewed by Letterman’s decision to take off the second week of the TV season.