something with specs maybe between what he uses now and a Wilson Pro Staff 6.0 95. I think he definitely should switch to a slightly bigger head size before he retires. At least, he should give it a try. 95 sq. inches would probably be the most he should go. I am sure he could have Wilson make for him something around a 93 sq. inches head with a slightly wider beam width to add a little more power. the big advantage is that a slightly larger head size will give him a little more margin for error. his current racquet has such a small sweet spot!