If Seattle were to land two new major sports franchises — an NBA team and an NHL team, as arena investor Chris Hansen wants — it would rise to the level of America’s largest cities with six major pro teams. Only New York, the Los Angeles area, the Bay Area, Chicago and Washington, D.C., have six or more major teams each.

Could Seattle even support two more?

That’s the question Tim Ellis, editor of real-estate site SeattleBubble.com, examined in a post this week on his personal blog. He looked at regions with NFL, MLB, NBA, NHL, MLS or WNBA teams, and left college sports — even though the Washington Huskies field a couple popular teams here — out of the equation.

Under that rubric, Seattle has four major teams: the Seahawks, Mariners, Sounders and Storm. With the current metro-area population, about 3.5 million, Greater Seattle has a population of around 875,007 people per team. That’s the current market for professional Seattle sports in this scenario.

If you add two more franchises, Seattle would have a population per team of about 583,338, Ellis calculated. That would rank second in the nation behind only Denver, which has 519,901 people for each of its five major teams. For comparison, New York’s population per team — with 11 major franchises — is 1.7 million.

“At 875,007 residents per local pro sports team, Seattle is already 25% below the 28-city average of 1,174,483,” Ellis wrote. “If we were to bring both NBA and NHL teams to our market we would shoot to a full 50% below the average.”

Ellis decided to look at the national numbers — number of professional sports teams versus metro population — after reading a Seattle Times report about the city’s Arena Review Panel meeting with the City Council. Councilwoman Jane Hague asked whether the Seattle region could actually support so many teams. Former Sonics coach and arena panel member Lenny Wilkens said yes; after his rough examination, Ellis says no.

“Obviously a more detailed analysis would take into account incomes, recreational spending patterns, and other factors,” Ellis wrote. “That said, we’re obviously not hurting for pro sports teams here in Seattle, relative to the size of our market. So why exactly do we need to spend $200 million in public funds to build a new stadium and bring two new pro sports teams to Seattle?”

Well that’s an entirely different discussion. And it should be noted that under the proposed agreement between Hansen, the city of Seattle and King County, that $200 million public investment would be paid back by revenue generated only by the new arena, its teams and its other entertainment events.

And while we’re playing devil’s advocate, there are a few other big questions that arise from Ellis’ blog post. I’m not entirely sure what they mean, but they’re good to bring up.

For instance, should he even factor in the WNBA? It is a major sport and the Storm are a popular pro team, but there’s no doubting there’s a much, much larger fanbase for the Seahawks and Mariners than for the Storm. One might even argue that the Sounders shouldn’t be considered.

Ellis took that difference into account for his charts showing the trend line for U.S. cities and the number of pro sports teams they host. His first chart put Seattle, currently with four teams, just above the trend line. For his second chart, weighting NFL, MLB and NBA teams as equivalent to two, Seattle is right on the trend line with a statistical “six” sports teams.

Another question is whether having a relatively low population-to-team ratio is really a bad thing. Denver, with five major franchises, seems to be doing just fine. Same with Minneapolis, which has five major teams and a metro population of 3.3 million — slightly smaller than Seattle.

Then again, there are other cities with low ratios that are already having trouble keeping their teams afloat. In Phoenix, which has five major franchises with a population of 4.3 million, the Coyotes NHL team are on the short list for possible relocation. In the Bay Area, which splits seven major teams among 4.4 million people, the Oakland Athletics can barely attract fans — though most relocation talk for the A’s has them moving only a few miles south to San Jose, still within the Bay Area. And even in the Big Apple, which 19 million call home, the New York Islanders NHL squad is having financial issues.

Each city, it seems, has its own unique situation. Who knows how Seattle would fare?

You can read the entirety of Ellis’ post, including several charts, on his personal blog.

Visit seattlepi.com for more Seattle news. Contact Nick Eaton at nickeaton@seattlepi.com or on Twitter as @njeaton.