I'm surprised that nearly all the views of ' resident' fish and this guys comment to lee is being seen in a negative or sarcastic sense from he should fish low stocked waters or catch emaciated overwintered fish!
Here's a positive angle on it some of which has been mentioned and are my reasons for preferring C&R venues so that I can catch resident stockies...
1. I like the challenge of wary fish and so also like my wild brownie fishing and even on stocked stretches of the Itchen get more of a kick out of catching a smaller wildie than another 3lb stockie.
2. The river isn't open all year and so resident fish are the next best thing
3. My definition of resident is one that has developed fully formed fins rather than the stunted versions' you often see on stockies. As result residents fight harder.
Put those things together and I personally get much more fun out of struggling to get close to my limit than trying to delay it so that I can extend my fishing time as has happened a lot on stocked waters I have fished.
I guess therefore my definitions of a resident are either a wild fish or one that has survived more than a year and so is likely to be fully finned too.
... And if a water is managed properly you shouldn't get skinny emaciated fish just because they have overwintered. If you did then venues like my club waters which are 95% C&R wouldn't work