McEnroe began evaluating Williams' chances in Saturday's final against top-seeded Victoria Azarenka, noting that he did not expect tentativeness to be a problem for the American star.
A 3-0 first-set lead is typically far too early to pencil any player into the next round, but it's hard to blame McEnroe because of the dominance Williams has displayed in New York the past 10 days. She has steamrolled opponents with astonishing ease, a streak that continued Friday with a 6-1, 6-2 victory over an overmatched Errani.
Even though Williams is a year older than Kim Clijsters when she retired last week and just a few months younger than Andy Roddick when he played his last match Wednesday, the 30-year-old American remains the most dominant force in women's tennis. She won Wimbledon, captured gold at the Olympics and stands one victory away from her 15th grand slam singles title.
Rather than waste words trying to sum up Williams' dominance, it's easier to allow some numbers to do it. Here's a by the numbers look at how untouchable Williams has been so far during the U.S. Open.
0: sets Williams has dropped in six U.S. Open matches
19: games Williams has lost in six U.S. Open matches
66: average number of minutes Williams' U.S. Open matches have lasted
29: Williams' average number of winners per U.S. Open match
8: Average number of winners per U.S. Open match by Williams' opponents
4: Losses in 50 matches this year sustained by Williams
1: loss in 10 career matches against top-seeded Victoria Azarenka, Williams' opponent in Saturday's U.S. Open final.