He has done his job, yet again.
The father and long-time coach of the girls prefers to head home rather than watch his daughters try to dismantle one another on the court.
"I can't even watch on TV," said the outspoken Williams. "I can't watch my daughters play each other. I'd probably have a heart-attack."
The illimitable Williams sisters, who collectively hold seven Wimbledon titles (five for Venus and two for Serena), will notch number eight tomorrow. That is a definite.
The only thing that remains to be seen is which sister will hold up the Venus Rosewater trophy at Centre Court after the match.
And, as is always the case, flipping a coin might give you your best chances if you're looking to guess the winner.
In 20 previous matches, the dynamic sisters have scored 10 victories apiece. They have split their four Wimbledon tilts, and in 2009, each sister has taken a match from the other in three sets.
The edge has gone to Serena when it comes to finals of Grand Slams, however. Serena has beaten her sister in two Wimbledon Finals (2002 and 2003), one U.S. Open final (2002), one Australian Open final (2003), and one French final (2002).
Venus, meanwhile, defeated her sister in the finals of the U.S. Open (2001) and at Wimbledon last year.
But Serena knows that her sister has become more dangerous on the Wimbledon grass in the past few years. Venus is riding a 20-match winning streak, and she is also in the midst of a remarkable streak of 34 consecutive sets won.
"Well, you know, I feel like going into this final I have nothing to lose," said Serena when asked about the daunting challenge of playing her older sister on grass. "I feel like obviously she's playing the best tennis at this tournament."
She got that right.
Along with winning every set, Venus has only dropped 19 games in the tournament, and has needed just six and a half hours to get it done.
Venus, while confident for many obvious reasons, is not taking her younger sister lightly.
"Even if Serena is not playing her best it's just that fight that she has, you're facing that. So there's so much to face when you play her, it's definitely a lot to get your mind around."
Venus, playing in her eighth final at the All England Club, is looking to become the first woman since Steffi Graf in 1993 to win three consecutive Wimbledon finals.
Serena doesn't have quite the legacy at Wimbledon, but a win would give her an 11th Grand-Slam title, drawing her within one of the legend Billie Jean King, who closed her career with 12.
For three sets tomorrow, the sisters will try to deny each other of achieving these milestones. But when it's all said and done they'll go home, share some dinner and have a good laugh about it.