PokerTracker

Is there a way to mark a date or hand on charts. I would like to be able to keep track of when I reviewed stats and made changes to my game. By having that point marked on the chart it would be easier to visualize if I was successful in altering my play and if that change resulted in more profit.

Something like that would require a custom statistic. This guide covers the basics on custom statistics creation and this guide goes into more detail. The latter was written for PokerTracker 3 but the techniques all apply to PokerTracker 4, the interface is just slightly different.