[Lexander]

The results you posted in my mind are pretty trivial in general (but useful to keep in mind). The chances that the river cards will hit the opponent are higher at that point if we assume that none of the previous cards have done so (which is required for your calculation).

I think the more interesting thing is that the river has three properties that make losing at the river more frustrating:

#1) You can't catch to win if you are behind at the river.
#2) You have generally put a lot of money in the pot that you have now lost.
#3) Many times your opponent made a poor call on the turn and got lucky.