ESPN

With an acknowledgment that the vagaries of fate and the pressures of competition may make this entire exercise moot, there's a good chance that this year's U.S. Open could yet again feature tennis' two most anticipated matchups: Roger Federer vs. Rafael Nadal and Serena Williams vs. Venus Williams.

Both rivalries have produced some of the best matchups tennis has seen in years. The Williams sisters have been neck-and-neck in head-to-head competition, with Serena holding an overall 11-10 advantage. The Federer-Nadal rivalry has been a bit more lopsided, with Nadal winning 13 of 20 matches from the Swiss legend. Whenever they meet, it's usually hard-fought and lengthy; their 2008 Wimbledon final match weighed in at a hefty four hours and 48 minutes.

Federer and Nadal are on opposite sides of the draw, so their only meeting could be in the final, whereas the Williams sisters, if everything goes to plan, would meet before that. Which match has more potential for excitement?

• With Nadal off the radar in recent months, most fans thought he only had the third-best chance to win.
• Similarly, though Serena and Venus are close in the rankings, fans saw the younger williams as the prohibitive U.S. Open favorite.
• Users RaulC16 and bball4life578 gave their predictions on Day 1; where did they differ?

“

When Serena has her "A" game, she plays such a stylish power game. Her precision in shotmaking and her focus make it fun to watch.

” -- brooklyn1006