Same with any common golfer, my bag is filled with second hand and brand new golf balls. Last year, I decided to strictly play one brand/ kind of ball only (ProV1x). This is to help me play better by being able to predict and expect the performance of the ball. However, I still drift from new and second hand ProV1x's from time to time. Of course because of monetary issues. Coincidentally, I always find myself playing bad when I use second hand golf balls while playing good when using brand new ones! Maybe it is due time that I start playing with brand new golf balls always??? For the meantime, I only reserve the brand new golf balls for tournaments/ leagues and important games while using the second hand for practice rounds...
I wonder if anybody else is on the same boat as I am...