Not another "my pro poker playing friend" story, this is just an analysis

friend1 plays 50/100 and has been in various tournaments
friend2 plays 10/20 and 20/40 regularly

I notice when either of them plays heads up or in a 3 way pot, they raise pretty much every hand, as long as it isn't absolute trash. While sometimes the swings come and they lose money, most of the time i've seen them take someones entire stack because this play style puts the other person on absolute tilt after losing a big hand.

The strategy, from what i've observed, is raise until you feel beaten, then call to the river regardless, this scares the person from bluffing you later

Then when you hit a solid hand, check raise it some, hoping the other person bets at you since he thinks he has you beaten.

to play 50/100 you have to sitdown with $3,000, i've seen friend1 take people's entire stacks doing this