We'll provide the numbers. You decide who's the bigger superstar.
But, between them, whose star shines brighter?
Let's run some numbers. Take a look and then vote for your favorite in the comments section below or by e-mailing email@example.com.
Let the (friendly) battle begin!
Round 1: Country Radio
Underwood jumps 12-10 this week on Billboard's Nielsen BDS-based Country Songs chart with "Blown Away," the title cut from her fourth album. With the advance, she maintains her perfect record of reaching the chart's top 10, as all 16 of her promoted (non-holiday) radio singles have reached the top tier, a record among women in the tally's 68-year history.
Underwood passes Swift, who has sent her first 15 such releases to the top 10. Can Swift keep the competition going with her latest, "We Are Never Ever Getting Back Together"? The song rises 19-18 on Country Songs after debuting at No. 13 two weeks ago (aided by promotional airplay its first two days by Clear Channel Media and Entertainment stations). Will "Never," co-written with master pop tunesmith Max Martin - ultimately be deemed too pop-leaning for country radio? Or, will it become Swift's 16th straight career-opening Country Songs top 10, keeping her in step with Underwood?
Both artists have also made multiple visits to the Country Songs summit. Underwood, however, has done so twice as much as Swift: Underwood boasts 12 No. 1s; Swift, six.
Round 2: Crossover Radio
As Underwood's music tends to be more core-country, Swift has seen more of her songs cross to pop and adult radio. Underwood made one appearance on the Pop Songs radio chart, reaching No. 9 with "Before He Cheats" in 2007. Underwood has placed six songs each on Adult Pop Songs (including the No. 20 hit "Good Girl" in June) and Adult Contemporary.
By contrast, the more pop-influenced Swift has charted 13 entries (her lucky number ) on Pop Songs, including "Love Story," which in 2009 became the first - and, to date, still only - song to top Country Songs and Pop Songs in the 20 years that the rankings have coexisted. She's made 11 appearances apiece on Adult Pop Songs and AC.
Round 3: Album Sales
Underwood has released four studio albums, with Swift set to offer her fourth proper studio set, "Red," on Oct. 22. So far, despite one fewer such effort, Swift leads: she's sold 17.8 million albums; Underwood, 13.4 million, according to Nielsen SoundScan.
Underwood, however, claims the highest-selling album among the two stars' outputs. Her 2005 debut "Some Hearts" has sold 7.2 million. 2008's "Fearless" marks Swift's best, at 6.6 million.
Round 4: Digital Song Sales
Again assisted by her greater crossover appeal, Swift far outpaces Underwood in digital song sales, although both acts sport extremely enviable totals.
Swift has sold 51.1 million downloads; Underwood, 24.9 million.
Round 5: Touring
Among 204 concerts reported to Billboard Boxscore since 2006, Underwood has sold 1.4 million tickets, generating $67 million in sales.
As impressive as those numbers are, Swift's shows have produced even wildly greater figures. Since 2007, an almost identical 207 concerts have been reported to Billboard Boxscore, during which time she's sold 2.8 million tickets - twice that of Underwood - and generated sales of $188 million, or almost three times as much as Underwood.
Bonus Round: Intangibles
Twenty-nine-year-old Underwood is married to Mike Fisher of the NHL's Nashville Predators. Twenty-three-year-old Swift is currently making headlines for dating Conor Kennedy, gifting tabloids with fodder over whether the famed Kennedy family would welcome her into their lineage.
Underwood won "American Idol" in 2005. Swift was Billboard's 2012 woman of the year.
Swift has won six Grammy Awards; Underwood, five. Underwood has won 11 Academy of Country Music Awards; Swift, six, with Swift having won coveted Entertainer of the Year honors the past two years after Underwood claimed the title in 2008 and 2009. Swift has won seven Country Music Association Awards; Underwood, five.
Underwood has won six People's Choice Awards; Swift, three. Swift has won 10 American Music Awards; Underwood, six. And, each has scored one No. 1 on the Billboard Hot 100, with Swift's "Never" currently seated at the summit.
Oh, and best not to cross either one. Underwood will take a Louisville Slugger to both of your car's headlights. And, Swift, of course, will never, ever get back together with you. (Like, ever).
Uh-oh, not so easy to pick a winner.
Or, do we even need to? According to Underwood, why bother when both singers have entertained audiences worldwide? (Best of all, they've also each helmed numerous philanthropic efforts, from Underwood's work with Country Cares for St. Jude Kids to Swift's contributions to the Red Cross, among others.)
"I feel like we're definitely completely different artists. That's something that's so cool about country music because everyone has their own thing," Underwood said  in June. "Our songs are definitely different. She sings a little bit lighter sometimes. It's just a difference in our brand(s) of country.
"For me, it's cool that we can bring more people into country music by being different."