Wow. You say don't have outdoor soccer games but you go indoors for gambling. Crazy. Yes masks help. No they aren't 100%. Indoors up to 20x worse than outdoors.The sovereign nation casino I attend checks everyone's temperature at the entrance, requires appropriate masks for all (no bandanas, for example), has shut down almost half the machines, and has reduced the number of seats at the table games.
Research suggests outdoor gatherings are safer than indoor events
According to Erin Bromage, a comparative immunologist and biology professor at the University of Massachusetts-Dartmouth, some research has shown that "[o]utside is definitely safer" than indoor gatherings when it comes to potentially transmitting or contracting the new coronavirus.
For example, the New York Times reports that, in a study that was released preprint and hasn't yet been peer-reviewed, researchers found that the chance of coronavirus transmission occurring indoors was nearly 20 times higher when compared with outdoors.
Further, in another preprint study that hasn't yet been peer-reviewed, researchers reviewed 7,000 coronavirus cases in China and found that just one of those cases stemmed from outdoor transmission, and the transmission likely occurred during a prolonged, face-to-face conversation.
Julian Tang, a virologist at the University of Leicester, explained that, generally, the more open a space, the less likely the novel coronavirus can become concentrated in one area in the air and then inhaled by another person, which can result in infection.
And this.

Do I Really Need To Wear A Mask Outdoors? Here’s The Science
Should you wear a face mask outdoors to help stop Coronavirus from spreading? The scientific research so far suggests that it's probably not necessary, but your decision should also depend on where you're going.
