HBO is known for its great miniseries. Is “Chernobyl” its greatest?

The latest in a long line of acclaimed HBO miniseries, Chernobyl is undeniably great no matter what measure you use. It’s a hit with TV critics, boasts the highest IMDb user rating of all time, and is generating more think pieces than readers can consume—always the hallmark of a culturally impactful series.

But is it HBO’s best ever? It’s close. Very close.

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From Band of Brothers to Angels in America to Generation Kill, HBO has been the home to TV’s most buzzy miniseries for decades. All shows that air on HBO have an air of prestige to them, but miniseries even more so. HBO’s miniseries tend to look back at important moments in history and culture with all the top-notch production values and cinematic verve that the pay-cable network can muster. Chernobyl is certainly no different.

A dramatization of the titular 1986 nuclear disaster and its aftermath, Chernobyl stars Jared Harris as Valery Legasov, a Soviet chemist who led the official government investigation into the causes of the disaster, which directly resulted in the deaths of more than 30 emergency workers and untold thousands more from cancer in the following years. Variety said the miniseries “build[s] a steadily creeping unease, allowing the scale of the atrocity to sink in with terrible, fitting gravity.” Vanity Fair called it “excellent television” and “paradigm-shifting historical storytelling.”

IMDb users rated Chernobyl as the best series of any kind in television history—higher, even, than the shows commonly considered to be among the greatest of all time, including The Sopranos, Breaking Bad, and The Wire. That is just one measure, however (and a rather unscientific one at that).

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To figure out whether or not Chernobyl is really HBO’s best-ever miniseries, Quartz combined its Rotten Tomatoes score, Metacritic score, and IMDb rating into one number and compared that to the total numbers of other HBO miniseries, where data were available. (Some acclaimed miniseries, like Angels in America, were missing one of the three criteria, and thus were not included.)

When you add up all three numbers, the HBO miniseries with the highest total score is… The Corner. Barely. The 2000 miniseries from David Simon, which served as a precursor of sorts to The Wire, bests Chernobyl by a single point. Chernobyl is tied with World War II miniseries Band of Brothers for second place.

A caveat: The Corner’s perfect Rotten Tomatoes score is based on just 12 reviews. It’s unlikely that the miniseries would remain at 100% if the aggregator had compiled as many reviews as it did for Chernobyl (57). Even with that many reviews, just one “rotten” review would knock The Corner down to 99%, putting it in a three-way tie for first place with Chernobyl and Band of Brothers. (For what it’s worth, Quartz could not find one clearly negative review of The Corner anywhere on the internet.)

While none of the three measures are perfect, they each quantify a show’s impact in slightly different ways. The Rotten Tomatoes score is merely the percentage of critics that gave a show a positive review, which generally (if imperfectly) gets at some kind of critical consensus. Metacritic scores are similar, but those actually assign a number to each review (usually decided by the site’s staff) based on how positive (or negative) it is. Metacritic scores are then averaged and weighted, based on a critic’s or publication’s reputation. (A New York Times review, for instance, will move the needle more than a review from a blog no one’s ever heard of.)

Finally, IMDb ratings are just the average of all the ratings made by the service’s many thousands of registered users—the populist score, if you will. (Since IMDb ratings are out of 10, Quartz scaled them up so they’d match the other two measures, which are out of 100).

Whether or not Chernobyl is the best, its success came at the perfect time for HBO—right as Game of Thrones ended. Not only does it help soften the blow of the fantasy drama’s divisive finale, but it’s also a positive start for HBO’s commitment to air original programming on Monday nights in addition to its usual Sunday night schedule. Years from now, we may look back at Chernobyl as the series that ushered HBO into the crucial post-Thrones era.

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