question, is one of the problems your wife is having crossing over do to not being lined up correctly or is it do to the ball finishing too hard on the backend and her not knowing what to do?? these are some questions you might want to ask yourself before changing things.. the degree 2000 polish will actual fill the scratches made by the 500 grit raising it to maybe 1200 w/a shine.. you might want to take the ball to your local pro shop and have them hit the ball with a 2000 abby pad then polish it.. have her try that and if you need more length try 4000.. just remember this will probably make the ball backend harder even though you are getting more length(the ball will save more energy).. another suggestion is to take the shine off the ball first and have your wife throw it like that(sorta dull), this will make the ball roll a little earlier and maybe stop he from crossing over if it is the backending part of the ball she is having problems with.. try a green scubby, if you dont have any abby pads and gently take the shine off the ball not pressing too hard.. if you see this is a better reaction on the ball you can have your local pro shop hit the ball with 1K, 2K, 4K abby pads leaving the ball dull.. the higher you go with the abby pads the more length you will get from the ball even though it is dull.. like I said the ball will roll earlier and not have as much backend if that is the problem.. the ball will probably hook alot in the beginning(fronts/heads) because it will have a new clean surface on it, but once some the lane oil gets on the ball it will tame the ball down some so it will go a bit farther before it actually starts picking up.. I hope this has helped you some and not confused you more.. good luck with your wife's problem...  slashrr69