I'm definitely not an expert on the subject, but I use plastic spare ball (drilled/weighted identically to my strike balls) on the solid ten. Starting from the far left, I aim for the third arrow from the right. I think many folks aim for the middle arrow. Practice hitting the ten as often as possible. During match warm up, throw a ball or two at the ten.

Hopefully one of the resident experts here can add more qualified advice.

There are a couple of things to consider:
- You want to shoot across the lane which allows for a larger margin or error of missing your target and still converting the spare.
- The term 'straighter is greater'

There is missing information, most importantly if your son is right handed or left.

The best way to proceed is to find a USBC Certified Coach and have your son work with that person. There are at least two schools of thought regarding the approach for 10 pins, so it's very difficult to provide you a quality answer in this type of blog setting.

One person suggested using a plastic ball though there are other ways to alter hand and wrist position. Again, you and your son will benefit most by one on one coaching from a USBC Certified Coach. go to www.bowl,com and use their search engine to find one in your area. I would suggest selecting someone who is either Gold, Silver, or Bronze certified.

Good Luck!