if you are looking for roto grip their hook rating system has been accurate for me and straightforward in basic terms.They have 4 general categories - HP4 - heavy oil or high performance- HP3 - Medium-Heavy oil - HP2 - Medium-Light Oil- HP1 - Light Oil. I personally would choose a ball from their HP3 and HP2 line. Depending on if you see more of should dictate your third ball. Dry conditions choose one from their HP1; if you see more oil choose one from the HP4 line. I have a rumble and scream, for the most part i can play all day with those two, but a lot of guys seem to be tearing up with asylum.