say what you mean and mean what you say.

No, I just know too much and know that peak user figures are a terrible measurement of the number of people playing a game. If 5 people are on during prime time instead of early morning because an Australian guild left the game, that doesn’t mean the game has grown. Lies, damned lies, and statistics.

do you let them drive, ride in cars, or walk near roads?

I don’t “let” them do anything. They’re autonomous people who make their own decisions, which means they may take risks they choose. I take risks with my own life, true, but that’s because the opportunity costs for never leaving home home (where, really, it’s not 100% safe) are too great. Anyway, there’s a world of difference between “Hey, let’s drive to the store allowing that we might get side-swiped by an semi,” and “Hey, point this loaded gun at your head and pull the trigger. I know the chamber is empty because I just checked.” I’ll leave it as an exercise to the reader why those are different.

Concerning your loved ones: do you let them drive, ride in cars, or walk near roads? There is a 1 in 10,000 chance per year that they will die in a crash. You are 99.99% certain that they will live through the year. You would not gamble their lives on a 110% certainty, yet you consistently gamble yours and theirs below 100%. Why? (My guess: at some point, you act on less than perfect information, as people seem to be objecting to. Sara thinks there are too many variables to talk about whether WoW will gain or lose subscribers this year, but Sara is probably willing to bet far more than $20 on a riskier question with more variables via things we call “weddings” or “moving for a new job.”)

No, actually I think you’re doing the opposite: being too intellectual for your own good. You’re trying to show a justification for saying, “Put up or shut up,” and it’s falling a bit flat. As I said, some people do create more noise than is worth. These people I ignore.

As for the “life of a loved one” extreme wager, my point was that sometimes some things are too dear to bet on; I figured that was one thing that most people would agree with. Depending on my existing financial situation, $20 would be too much for me to bet on something I’m really sure about (2009 was a terrible year for contract work). Just because I was willing to wager $20 on something a few years ago but not today doesn’t mean I believe the previous thing any more strongly.

In the update, Zubon wrote:
If your beliefs will never be testable, as I said, you are just making noise….

This is the point I strongly disagree with. I think an opinion such as, “I think World of Warcraft is losing subscribers.” is interesting even if it’s not verifiable by most people. Without data that Blizzard doesn’t share, we can’t show this conclusively. Sure, we can approximate by looking at “peak times”, but you’re just adding uncertainty.

Ultimately, I think your point is that people do a terrible job of separating out fact from opinion, and I agree with that. I’ve been accused of passing off my opinion as fact before, usually by posing as an authority. But, I think you’re going a bit too far here in that you’re essentially saying opinion is useless.

On proving a negative: of course we do that all the time. We have a mention of Bayesian updating above, and absence of evidence really is evidence of absence (of varying strength). If your theory predicts that X should be there, and it is not, that is evidence against your theory. Most of us are pretty confident on the question of whether werewolves exist, even without a deductive proof on the matter.