Some of these men and women may not make it to the second week of the U.S. Open (then again, you never know), so look for them in the early rounds
• After Serena Williams (No. 31), Germany's Sabine Lisicki represents the biggest differential between a player's ranking and her ability. After missing the better part of a year with an ankle injury, Lisicki, who has the hardest serve in women's tennis (it's been clocked at 121 mph), dropped out of the top 100. She's back with a bullet, fresh from reaching the Wimbledon semifinals, at age 21. Her ranking is 23, but don't be fooled: This is a top 10 talent.
• Like the Canadian dollar, Canadian tennis is, unthinkably, threatening to surpass its U.S. counterpart. At the start of 2011 Toronto's Milos Raonic was ranked a lowly 156. Riding his elephant gun of a serve, the 20-year-old was in the top 25 by Wimbledon, making him the highest-ranked Canadian. A hip injury stalled his progress in London, but if he's healthy in New York, put the 6'5" Raonic, now ranked No. 28, on the short list of players to follow.
• A year ago Alex Bogomolov Jr. was a washed-up former pro, giving lessons at tennis clubs in the New York City suburbs. Then he decided to give his playing career a last shot, financing his travel with a credit card. Winning begat winning. Now the 28-year-old Bogomolov, the son of a former Soviet national tennis coach, is in the top 50, has recently beaten Andy Roddick and Jo-Wilfried Tsonga, and has won more than $250,000 in prize money for the year.
• Given our propensity to hype U.S. women who show even flashes of promise (see: Oudin), optimism about Christina McHale should be guarded, but it's hard to ignore her progress. A 19-year-old from New Jersey, she is nearing the top 50 and upset top-ranked Caroline Wozniacki last week in Cincinnati. McHale is light on weaponry but heavy on consistency and resolve. Given the volatile state of the women's game, those virtues could presage success.
• While his father drove a cab around Queensland, Australia, Bernard Tomic became adept at piloting tennis balls around the court. At 18 he is already ranked 61st, fresh off a run to the Wimbledon quarterfinals that included upsets of Nikolay Davydenko, Robin Söderling and Xavier Malisse. Standing almost 6'5", Tomic hits the ball with such force that, inevitably, he'll be nicknamed A-Tomic. Provided he improves his movement, he'll be a star.
• Inasmuch as there is a young U.S. men's hope, the distinction-cum-burden goes to Ryan Harrison, a 19-year-old Texan. Now up to No. 78 in the rankings, Harrison made a minor run through the qualies and to the fourth round at Flushing Meadow last year and has been improving ever since. Still filling out his six-foot frame, he already has a versatile game and—unlike too many recent U.S. prospects—drips with intensity and focus.
• You think Novak Djokovic has had an impressive year, losing just two matches? Then consider Esther Vergeer, who hasn't lost since January. Of 2003. The 30-year-old player from the Netherlands, a five-time U.S. Open women's wheelchair champion, is riding a dumbfounding 422-match winning streak. Watch her while you can, and remember her the next time you hear another athlete described as "dominating" a sport.