Yes, if you are a whimp anger can turn into fear. Usually, when one gets angered, it is the result of an external pressure.
At this point, you have a choice - fight or flight. Whimps turn in fear and cry MOMMY MOMMY!!.
In an 8 ball APA playoff, I was down 2-1 and their team captain shouted: "Turn it up a notch. Turn it up a notch." I got very angry and when my opponent broke and missed I ran the next 4 racks and out. I completely went into the zone and was so focused I didn't hear or see anything but the pool table, the balls, and the clicks.
I have seen plenty of players get angry and do this.
Black Jack, I respectfully disagree with your assumption.
I don't want to get into this too much, but to answer another poster's question about how you funnel this, the trick is to use anger as a 'trigger' to put you into the zone. RandyG and Fast Larry come to mind when it comes to using 'triggers'. If you go into the zone to long, you will get tired at the end of a deep zone, usually one hour. The trick is to go into a mild zone and hit the trigger switch to get out of the zone before you tire. Sorry to go off on a tangent, but the key here is the 'trigger'.
Ray,
We will have to agree to disagree. "The zone" is an altered state of consciousness. It is characterized by the player having perfect harmony in their thoughts, emotions, and actions. There is no room for anger.
"Angering" yourself into the zone will make those "deep zone" periods much shorter for obvious reasons. More times than not, if you are overly emotional about the external, the zone will be unavailable to you. Using anger as a trigger won't work either. Anger leads to outbursts (inwardly or outwardly). What I think we might agree on, is the fact that
the presence of anger needs to be recognized first. Once it is recognized, you must have cue phrases or triggers that lead your mind and thoughts towards control, NOT what triggered the anger. This is accomplished by (as you said) using triggers. However, you must use triggers that lead you toward positive thought and emotional control, not anger.
Outbursts of anger are signs of loss of emotional control. Outbursts are fine, as long as you are able to regain and maintain control afterward. If the player remains angry, there will be no control, more emotional outbursts, mumbling, ranting, and eventually a loss of confidence.
Fear is a natural emotion and a natural response in high pressure situations. All anger is based in fear. It could be fear of losing control, losing a match, not making a shot, consequences thereof, etc. Anger is used as a primal response to fear, and it is actually deceptive to what is really going on behind the eyes.
Plain and simple, anger masks fear. While in the zone you must be in control of your thoughts, actions and emotions. If you are angry or fearful in the zone, then chances are you aren't there anymore.