The only TV market more valuable than the one in Los Angeles is the one in New York. When USC and UCLA leave the Pac-12 for the Big Ten, the conference will still have places like Seattle, Phoenix, and the Bay Area to lean on, but TV homes does not equal TV eyeballs.

Gauging what kind of loss the two Los Angeles-based teams will be for the Pac-12 when it comes to its ongoing discussions over the league’s next TV deal has been the topic du jour since the news broke earlier this week. Discerning the difference between interest and access is the key factor.

The departures are damaging to the Pac-12, given the timing. How damaging?

Very, according to longtime Pac-12 columnist John Canzano, who reached the former president of Fox Sports Networks for comment this weekend.

Bob Thompson, the former FOX exec, told Canzano he anticipated the Pac-12 signing a deal that would bring in somewhere in the neighborhood of $500 million a year for the league to distribute amongst its peers. That estimation included USC and UCLA.

Without those two, Thompson estimated the annual number to be closer to $300 million.

“They just lost their largest TV market in LA and ostensibly lost San Diego, Santa Barbara, and Palm Springs DMA’s as well,” Thompson told Canzano.

Those numbers are sobering for the league, simply put.

At full strength, $500 million is still only half of what the Big Ten is expected to agree to for its next TV deal. With USC and UCLA joining the Big Ten, that league could stand to make even more.

The gulf between the two leagues is wild and could continue to grow depending on what happens with Oregon and Washington. The Pac-12’s media rights agreements expire in 2024. We wrote about next steps for the conference and for its individual members here.