Even more fun: speculate on and completely make up an opponent's position, then argue against that.
The example in practice from Mike Florio at Pro Football Talk. Speculating on why Brad Childress elected to punt (and essentially give up on the game), Florio writes:
"Maybe the truth is that Childress feared backup quarterback Tarvaris Jackson, who replaced Gus Frerotte after his hand split open and gushed blood like watered-down gravy spilling from a ladle, would convert the long fourth down, and then perhaps would get a few more of them, and then perhaps would lead the team to a touchdown, requiring Childress to then perhaps revisit his decision to bench Jackson.
"A good coach is smart enough to realize that a quarterback who regains lost confidence can only help the team, even if it requires the coach to deal with internal or external voices clamoring for another change."
It's not just that the speculation is stupid (if anything, I think the opposite is true: Childress just saw Gus Frerotte leave with injury, and just saw Jackson take two straight sacks because he held onto the ball too long. He may have decided he might need Jackson in the future and he didn't want to utterly destroy his confidence in a bad situation. Or he didn't want Jackson to get hurt in a bad and dire situation, possibly requiring the team to start Booty. I don't like that argument, but it's more likely speculation). It's that after making up this speculative reason, Florio bothers to argue against that speculative reason. That he entirely made up. And that is very easy to argue against.
The Straw Man, ladies and gentleman.
Criticism of Brad Childress' ability to be head coach of the Vikings is entirely justified. Criticism of Brad Childress' decision to punt the game away is entirely justified.
But this fallacious argument is just stupid.