[RightWhale]

A knife against a bear is at least potentially winnable. Daniel Boone did it, although it was a black bear, something that one could wrestle. To get behind the bear and hang on while trying to get the point into a neck artery would be the plan. A spear might work, too, since that is confusing to animals.

[Travis McGee]

I think the idea with a spear against large dangerous game is to plant the butt end in the earth, and let the charging animals momentum impale him.

I guess you gotta be a pretty cool customer to pull it off, since you'll only get one chance to make it good, and if Mr. Griz or Simba swats it aside, you're lunch.

[ExSoldier]

"A knife against a bear is at least potentially winnable"

I dunno, I remember seeing that movie: "Legends of the Fall" and it ended on a rather fatal "bear v. knife" type note for the knife holder.