I figured it out. The post appeared twice because I was using my cell phone. The first post went thru but the outgoing post remained on my phone and at some point I pressed something on my phone which sent it again. (I was still on the reply page of the forum.)

What Rob wrote about The Wizard supports what I said. We all agree Mike is an expert at the math of gaming but that doesn't necessarily means he wins.

You don't have to win to be an expert.

If experts always won, APs would never have losing sessions.

It's luck that your expert knowledge coincides with the shuffle, or the roll, or the spin, or the choice of the RNG. Knowledge alone doesn't make anyone a winner -- it helps -- but you need luck.