The PGA Tour continues to balance the risks of positive cases. But which risks exactly?

A PGA Tour bubble is a noble if not simple objective.

The concept upon returning to competition earlier this month was quite basic: to shield tour events, including players, from the risks of COVID-19 even as the virus surges in parts of the U.S. The reality, as made apparent by a handful of positive tests in recent days, has proven far more elusive.

“It’s a myth,” Dr. Matthew Binnicker, director of clinical virology at the Mayo Clinic in Rochester, Minn., said of the possibility of an operational bubble that zig-zags across the country, with hundreds upon hundreds drifting in and out of its path every week. “Even in health care, there’s no way we can operate at zero risk. You have to take steps to mitigate and lower risk, but with this virus you can’t put in place anything other than saying everyone has to stay at home inside their house.

“It’s impossible to operate inside a bubble. It’s not real life.”

That the Tour, though exhaustive in its efforts, would be exempt from reality is of course as much a fantasy as a J.K. Rowling novel, something it seems acutely aware of. Yes, officials knew there would be positive tests, which is why it made several suggestions within its protocols to mitigate the risk.

“We feel like we put ourselves in a position where we can have a controlled environment or a controlled number of cases or positive cases going forward,” Commissioner Jay Monahan said on Wednesday.

What’s become apparent is there’s very little that the Tour can truly control. Its guidelines are merely that, and as such not enforceable. Even if in use, in order to be effective, everyone—players, caddies, coaches, trainers, equipment reps, wives, girlfriends, nannies, chefs, et al.—would need to abide. Total adherence is difficult if not impossible given human nature. Even the commissioner conceded as much.

“When you get in the environment in the tournament, with no spectators here and with very few people here, with people that are around you having tested negative, I think over the first couple weeks, we’ve seen some instances where let’s say we’ve gotten a little bit lax or away from protocol,” he said. “Full disclosure: I’ve done it myself.”

To wit, on Tuesday, Brooks Koepka spoke of the lengths he has gone to in order to maintain a bubble with his team. But his chef still needs to go to the grocery store and last week, Koepka’s caddie, Ricky Elliott, attended the funeral of a friend in Orlando, where he was joined by Graeme McDowell and his caddie Ken Comboy. Elliott and Comboy later tested positive. Koepka, who stayed in the same house with Elliott in Hilton Head, and McDowell, who spent six hours in a car with Comboy on his way to the island and roomed with him once there, withdrew from this week’s Travelers Championship for precautionary reasons. Likewise, Brooks’ younger brother Chase also withdrew, as did Webb Simpson when he discovered a family member he’d been around tested positive.

Though McDowell, both Koepkas and Simpson have since tested negative, it doesn’t take an infectious disease expert to connect the dots on the possibility of spread. We asked one anyway. “When someone is infected and around someone who is susceptible to the virus, the rate of transmitting is in the range of two to three additional people,” Dr. Binnicker said.

Never mind that many players and caddies, and those in the various “bubbles” also live in Arizona, Florida and Texas, all currently viral hot zones. Cameron Champ, who withdrew from the Travelers on Monday, tested negative at Colonial three weeks ago, went home to Houston for a week, flew privately by himself to Connecticut and tested positive when he got there.

So what are the various risks and their levels of concern for the Tour as it marches forward in its porous bubble? They are numerous but also dependent on a number of factors.

On the golf course

Inside the competition remains the safest and most controllable environment for the Tour. Outdoors, no fans, easy to social distance—though there have been habitual norms like fist-bumping and exchanging of clubs and towels between player and caddie that have been difficult to shake.

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“Golf is probably one of the safest sports in terms of risk of transmission, versus a sport like basketball or football, where the athletes are interacting in close proximity,” Dr. Binnicker said. “If you maintain distance, especially outside, six feet apart, and you’re wearing a mask, the risk is very low, less than 1 percent.”

Players and caddies are not wearing masks during competition, and indications are that only a small percentage of them are wearing them elsewhere on property at a tournament, but the open air and with an ability to spread out the risk decreases significantly. Things get tricky from there, however.

Clubhouse, locker room, other enclosed spaces on site

The next highest level of risk is within the confines of the structures of the courses the Tour travels to week after week. The same principles about mask wearing and social distancing that apply outdoors similarly apply in these environments, but the risks go up in enclosed spaces.

“Indoor events have a little higher risk because outside there is more humidity and respiratory droplets from people are bigger and fall to the ground faster,” Dr. Binnicker said. “Inside, it’s not as humid so those respiratory droplets are smaller, stay in the air longer and spread farther.”

Hotels and other accommodations

Though the Tour has provided host hotels each week as an extension of its bubble, protection is something of a fallacy because they are merely blocking off rooms rather than taking over the entire property, meaning there are hundreds of other people to account for who are coming and going.

A rented house may indeed be a better option but even that relies on its occupants, both current and previous, and their actions. A handful of people shacking up in the same shared space for a week could be as problematic if not more so than a hotel.

“We worry when an individual with COVID is around other people who are susceptible for more than 10 minutes,” Dr. Binnicker said. “That’s the time we go from low-risk to high-risk exposure. That exposure can be reduced by wearing a mask. Talking to each other for 30 minutes, the risk isn’t zero but with a mask the protection rate is in the 80-85 percent range.”

Restaurants, bars, other public settings

Then there are the casual elements of everyday life, from dining out, to catching a movie or hitting the mall. Restrictions vary by state and city but as Justin Thomas noted last week, Hilton Head, a popular vacation destination with few restrictions and now with a spike in cases, was a “zoo.”

Engaging in such environments therefore presents a much higher risk. It is also another element that is ultimately out of the Tour’s reach in terms of control.

“Being in a small, confined bar or restaurant where people are huddled around, we’ve seen bars in Florida, for example, be some of the biggest sources for COVID over the last week or two as people go out,” Dr. Binnicker said. “That’s a real hot spot for transmission. You’ve got people talking loudly, not wearing masks because they are drinking or eating. It’s a prime location for the spread of the virus.”

Airplanes

So, too, of course are commercial flights and all the elements associated with barnstorming across the country.

Some players fly privately, and the Tour has offered a charter from one tournament to the next. But it gets more complicated and riskier for those who take commercial flights and when those in the bubble come in and out of it in between events. Put another way, there’s no way of knowing what a player is doing on his off week.

“The risk goes up quite a bit having a similar group of athletes going from city to city because they’re getting on a plane and interacting with more people,” Dr. Binnicker said. “I wouldn’t want to have to play in Jacksonville (Fla.) or Arizona right now because the number of cases are way up.

“Moving a group of people is higher risk than being in one location. It really depends on the actions of all those people. If you have control over those people, they’re doing a good job wearing masks and maintaining distance, the risks will be a lot lower. But if you’re not doing a good job after the work day is done the risk is a lot higher.”

Now what?

The Tour has implemented more protocols to its plan with an additional test for those arriving via charter, coaches now included as part of testing and bringing its fitness trailer on-site and requiring all those inside it to wear masks.

But there are still uncertainties even when it comes to testing itself. In short, a negative result isn’t necessarily a blank check.

“If some tested negative at tournament it means something for a day or two,” Dr. Binnicker said. “If they go back home and are interacting with people, the result of the test the prior weekend doesn’t mean much anymore because they can be exposed to others.

“Golf tournaments having testing prior to each tournament is a good idea. It gives them a snapshot. But it’s difficult to know or control people’s actions. Just because you test negative on Day 1 doesn’t necessarily mean you’re going to continue to be negative for more than few days unless you quarantine.”

So why doesn’t the Tour test every day?

“One of the things that we committed to when we committed our testing protocol was to not take away resources from every community where we are moving to and where we are playing,” Monahan said. “So there’s a finite number of supplies we could get at that point in time. Secondly, when you go back to our medical advisors, as we have done, and this is something we continue to talk to them about, and you look at CDC guidelines and you look at the expectation of any business like ours that’s reopening, testing every other day is a sound and accepted protocol for the environment that we’re in.”

As for the rest of the myriad risks that exist, the Tour, in essence, has said it’s willing to take them.

“I think we all need to remind ourselves that we’re all learning to live with this virus, and we all need to learn to live with this virus, both as individuals, as family members and certainly within our businesses,” Monahan said. “It’s pretty clear that this virus isn’t going anywhere.”

When it comes to pausing its season again, the Tour isn’t budging either.