Quote from boots:
What if you just roll down the Put and leave the Call alone?
(The more I learn the more I don't understand how I have been doing so well....dumb luck I guess)
boots
Simplistically, rolling down just the PUT is widening the vertical i.e. you are adding risk to the position.
The collars you are trading are relatively high probability and given a bull market you will most likely have been experiencing the max profit on these verticals more often than not!
Hey, if it ain't broke, don't fix it. Go fishing and don't worry about it

MoMoney.