Ants, One main thing to keep in mind about fishing is there are no set rules. Over time certain techniques have become standard because they work. That doesn't mean other ways wont work or shouldn't be tried. Some techniques are better in some situations than others, so it's best to learn as many as you can. I fish streamers more than anything else and I fish them casting upstream,across stream,down stream ,on a tight line,slack line and any other way I find that will help me catch fish.Most of the time I fish them with a tight line so I can detect takes or feel the strikes(the tug is the drug).After breaking a few big fish off you learn not to strike to hard.When fishers say it broke me off what they really mean is I set the hook to hard and I broke it off.
 
Ryan

What really determines what amount of "angle" you can get away with and still get a good set is mainly the hook size; the stiffness of the rod plays a smaller part. If you are using a size 20 Adams, a set with just the flex of the rod will work. If you are using a size 10 streamer, you might get away with a slight angle unless you have a very soft rod. If you are using a large saltwater fly, like a size 2/0 for example, you will need a straight line pull to set the hook. A sharp hook always helps, especially with large hooks. In the example of bass fishing you mentioned the rods are usually stiff and the line is high lb test so you will see that kind of set used. What matters is, you have to apply enough force to the hook point to get it to penetrate.

I've watched Midger catch fish after fish using a small streamer (like a 12 or 14) with a small tail fly like a midge.  He cast upstream and allows the flies to go with the current and then strips back up.  He caught as many on the trailing fly as the streamer and caught them in all phases of the drift and retrieve.

i always point the rod directly at the Streamer as i fish it, no matter if I am swinging, dead drifting, active retrieve, etc.. You do not want to have the Tip up and a bow of slack line between the rod tip and the Water.. because when you get a strike and slip strike all you will do is Bow the rod tip down and this will cushion the strike to the point You will not drive the Hook home. "Straight Line Contact" is very important when you are fishing Streamers (be it for Trout, Bass, Stripers and certainly out in the Salt, because you are going to strike harder and stronger on a Streamer take then on Nymphs or Dry flies...
 
also never fish Streamers on tippet lighter then 6 lb. test (and that's for small ones #10 ~ #14).. the Trout won't care about the heaver line, the flies are bigger and you need to turn them over on the Cast and while You will not get Quantity, You will most certainly hook Bigger Fish that are moving a great deal faster then they would to a Nymph or Dryfly.. so the extra "security" of a heaver Tippet is very much needed...

Streamer fishing is fun.  However, I am a sucker for comments that help me learn.  For example, this incident should allow some comments by me and from others on the forum.  
 
From the sucker’s viewpoint – OUCH!!
 
Of course, the fish was released and it promptly headed away form me.  
 

The direction of the cast was where the fish were located.  
The depth of the retrieve got down near the bottom.  
The bead head on the number four streamer dives like a bomber when the retrieve is paused.  (sorry sucker – you are probably quite aware of the fly action).
The strip set is effective.
 
Of course, in the same area the prior day, the results were a little different.  
 Fishing with streamers again without the bead head.  
 
It is not quite a two-handed fish, but the results are getting closer.  
I guess I may need to look for a larger net if I keep continuing.  I wonder where Stanberry gets his nets.  Of course, I will probable head toward the “modest” end of the rack.  
Happy Holidays!
Ants