“Here’s what I would say to anybody who any time they hear the word guns automatically goes off, like, ‘Oh, they’re going to repeal the Second Amendment,’” Costas said. “Let’s make a bet, you and me. Let’s say over the next five years we’ll do a Google search. We’ll have an independent party monitor it. You keep track of how many good and constructive things are associated with athletes having a gun, and I’ll keep track of all the tragedies and criminality and folly. And let’s see who comes out ahead or behind as the case may be.” . . .The problem here is a simple one. It would be a fair bet if all the defensive gun uses got media attention, but athletes have little incentive to report every time that they use a gun defensively. We know that people generally don't get news coverage for their defensive gun uses, and given how the leagues feel about athletes possessing guns, athletes have very little incentive to report these cases.
The problem might be that Costas actually believes that he will get an accurate representation of the rate of defensive guns uses from the media coverage. If you want a good idea of how the media only tends to cover bad news from guns and not their benefits, see this discussion here.
An additional problem arises if Costas is willing to concede that the possibility that athletes have guns serves as a deterrent for criminals. Put it this way: Would Costas be willing to put up a "Gun-free zone" sign on his home? He might feel that he can hire enough security protections that he doesn't need it, but I suspect that he still wouldn't put up such a sign. If so, even he must acknowledge that simply counting newspaper stories, even if they accurately recorded all events, would still not provide an accurate reflection of the benefits of gun ownership.