In the forecast for the match between Billy and Charles, I lean towards Billy's victory. He has already beaten Charles twice in Nottingham, which creates a psychological advantage. In recent years, Billy has been better at holding serve, which could be a key factor in success. It is also worth considering that in this match, Billy is younger and likely better physically prepared, which could help him in a tough battle. It is very likely that he will be able to defeat Charles again and advance to the final of the tournament.
