Tennessee and Kentucky are longtime rivals on the field and the court, but the coronavirus has inflamed tensions between the states, pulling a familiar debate into matters of life and death.

One graph built by a Kentucky educator took on a life of its own, going viral and fueling sniping from both sides. The graph showed Tennessee's virus cases spiking higher than Kentucky's.

Politicians on both sides of the border have pointed to those and other statistics to make the case that their state is tackling COVID-19 more effectively. Social media commentators have jumped into the fray, eager to declare a winner.

But while experts say direct comparisons can offer some lessons at this point in the crisis, they stop well short of a final verdict.

It's more complicated than that.

"In the United States, it's very difficult to compare states to states," said Dr. David Aronoff, director of the division of infectious diseases at Vanderbilt University Medical Center. "Testing is different, population is different, health disparities are different, reporting might be different."

Stephanie Jolly, the woman who created the attention-grabbing graphic in March, agrees.

Jolly said she posted the first graph on March 19 to provoke thought. Pitting two states against one another wasn't the point.

"This was never to say that the Kentucky model is best, the Tennessee model is false," Jolly said. "It's too early to know."

Jolly said she wanted her graph to highlight the power of social distancing and public policy. As the crisis evolved, she added to her model to reflect many different and changing variables in each state.

Her work highlights Kentucky's early steps to close schools and restaurants and encourage social distancing. Tennessee later took the same steps.

Now, Tennessee has become a leader in testing its population more broadly, which could play a role in its higher share of confirmed cases.

Kentucky has fewer confirmed cases in total and on a per capita basis, but Tennessee has tested at nearly double the rate of its neighbor to the north with more than 1,100 tests per 100,000 residents compared to 620 for Kentucky (chart below).

Kentucky's death toll of 115 on Tuesday was nearly even with Tennessee's 124 deaths, even though the Volunteer State has identified more cases.

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Political differences between the states have exacerbated the scale of the fighting, said Kent Syler, a political science professor at Middle Tennessee State University.

Kentucky Gov. Andy Beshear is a Democrat and Tennessee Gov. Bill Lee is a Republican, factors that likely heightened the debate's impact on a national audience, Syler said.

"We are so polarized as a nation that we can politicize most any issue and break it down to red and blue," Syler said.

"And then you get the sports element in it," he added. "You had all the elements there. It didn't take much to light the match."

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Governors and other elected officials weigh in

Since Jolly’s initial post on social media, elected officials, including the governors of Kentucky and Tennessee, have taken on the debate over which state is outperforming the other regarding the response to COVID-19.

Last week, Mason Barnes, a judge-executive in Simpson County, Kentucky told The Courier Journal he hoped Beshear would close his state's border to prevent Tennesseans from entering.

"We just took more proactive steps in Kentucky sooner than Tennessee did, and living on the Tennessee border right here with I-65, I can't keep the people from coming up here and taking advantage of the tax breaks they get on items and groceries," he said.

Barnes' comments came just days after Tennessee House Speaker Cameron Sexton shared an image on Twitter noting Tennessee’s COVID-19 testing in a week was more than what Kentucky had done in a month.

After issuing a stay-at-home order in late March, Beshear said his state had taken “very aggressive steps” while telling residents to “not go to Tennessee.”

Tennessee Lt. Gov. Randy McNally called Beshear's comments misleading.

Days after Beshear's comments, and after issuing his own order requesting Tennesseans to stay at home, Lee stopped short of directly criticizing his counterpart but noted the Volunteer State had performed significantly more testing than Kentucky.

In recent days, Lee has frequently noted Tennessee’s growing testing totals, largely driven by private-run labs. On Monday – after officials indicated just two tests were performed at state-run labs the day before – Lee downplayed the issue.

“As the testing turnaround has improved, where those tests occur are not nearly as important as they once were,” he said.

Department of Health Commissioner Lisa Piercey said the low number of tests at the state’s labs came during the Easter holiday. During the same time period, private labs processed 5,400 tests.

On Monday, Piercey said the testing capacity by private labs is one of the reasons Tennessee is able to begin discussing restarting the state’s economy.

“The private lab capacity is not nearly as robust in other states as it is in ours,” she said.

Both Tennessee and Kentucky have faced criticism

While much has been made of the differences between Kentucky and Tennessee's handling of COVID-19, both states have seen their own internal criticisms and efforts to improve.

After Tennessee was blasted for declining to share which counties had confirmed cases of the coronavirus, the state Department of Health shifted course, releasing the data. More recently the department has been providing more detailed information, including age and gender, as well as information about patient conditions.

Lee spent days facing scrutiny, and a growing chorus of calls from medical professionals, for his decision to not issue a stay-at-home order.

Lee initially announced a less stringent executive order on March 30 urging residents to stay home. He later changed course to require staying home, citing data that showed Tennesseans had increased their movement.

In Kentucky, state officials have worked to ramp up testing by joining forces with grocery giant Kroger.

Beshear has not faced much criticism in Kentucky for a weak approach to COVID-19. But he did get strong pushback from Republicans over a plan aimed at preventing churches from holding in-person services on Easter Sunday.

Beshear ordered Kentucky State Police troopers to be present and record the license plates of any who attended a planned mass gathering, which would be shared with local health departments to enforce a 14-day quarantine for all attendees.

Kentucky's Republican Attorney General Daniel Cameron said he was "deeply concerned" that law enforcement was asked "to single out religious services," calling that action “arbitrary.” U.S. Senate Majority Leader Mitch McConnell said Beshear should protect the public “without trampling basic constitutional principles at the same time,” and fellow Republican Sen. Rand Paul tweeted “someone needs to take a step back here."

Political volleying and interstate rivalries aren't likely to subside any time soon, but Syler, the MTSU professor, cautioned that there is much more to the matter.

"We keep falling back to a lot of the labels and divisions we have," Syler said. "This issue, and virtually every other issue that we confront, is more complicated than that."

Aronoff, the Vanderbilt doctor, cautioned people not to put too much stock into comparisons between different states. It is likely more informative to compare states against themselves to accurately measure the impact of different policies and behaviors.

"We need to keep our eye on our own dashboard moving forward," Aronoff said. "We can look at our curve and we can see how it changes over time in the light of changes in policy."

Tennessee and its neighbors

How Tennessee compares to its neighbors, with data as of April 14.

Georgia reported more than 14,200 cases among its 10.6 million residents.

Virginia has 6,100 confirmed cases among its 8.5 million residents.

North Carolina has 5,800 cases among its 10.4 million residents.

Arkansas has 1,400 cases among its 3 million residents.

Mississippi has 3,000 cases among its 2.9 million residents.

Missouri has 4,600 cases among its 6.1 million residents.

Kentucky has 2,200 cases among its 4.5 million residents.

Alabama has 3,900 cases among its 4.9 million residents.

In terms of reported deaths, Tennessee’s 124 falls behind Georgia’s 501, Virginia’s 154, and Missouri’s 133. Kentucky, which has more than 2 million fewer residents than Tennessee, has logged 115 deaths.

In some categories, Tennessee outpaces some of its surrounding states. For example, 633 Tennesseans have been hospitalized, compared to the 418 hospitalizations in North Carolina.

Mississippi has had more than 9,400 of its total 37,700 coronavirus tests completed by the state-run labs. By comparison, state-run labs in Tennessee have completed nearly 4,800 tests.

Of Tennessee’s surrounding states, only Mississippi and Georgia report the number of tests by private labs and state-run facilities, with the rest sharing an aggregate total.

Three surrounding states — Kentucky, North Carolina and Virginia — issued stay-at-home orders before Tennessee. Four took similar action days after Lee. Arkansas is the lone state bordering Tennessee that hasn't issued a stay-at-home order.

Joe Sonka of The Courier Journal contributed to this report.

Reach Adam Tamburin at 615-726-5986 and atamburin@tennessean.com. Follow him on Twitter @tamburintweets.