By Charles Bricker

Serena and Venus Williams open play tonight (which is tomorrow in Doha) in the Sony Ericsson WTA Championships, a reminder that as long as they are on court the U.S. will have a major presence on the game's world stage.

As for the rest of the American women out there in search of stardom, some will continue playing ITF events the rest of the year in search of a few bucks and more ranking points or they will call it a year and start recuperating physically and emotionally for 2010.

So, where does that leave U.S. women's tennis with the WTA's regular season done and bagged?

I would say certainly improved over where it was at the end of the 2008 season, but there remains significant uncertainty about who will fill the void when the Williams sisters leave tennis -- though admittedly that could be three or four years from now.

There is that noted Russian killer Melanie Oudin, who just turned 18 and who has had, on balance, a very successful year and who has gone from No. 177 at the start of the season to No. 47 today. I love her game. I love her competitiveness. I am not completely convinced she is a top-10 player. More on that in a bit.

Behind Melanie, there is a dark hole of mediocrity in the age range of 16-to-19, though beyond that I have very high regard for 13-year-old Victoria Duval and 14-year-old Sachia Vickery, a couple of precocious Floridians.

But that's off in the future. The here-and-now list of prospects behind Oudin is not so rosy. Jill Craybas, a career top-27, is a year-to-year retirement question. Vania King is young and has had her best year, but it's hard to see her making a major impact on the game. Bethanie Mattek-Sands is fighting injuries. Until she can get fit, she can't be counted on to break even top-50.

It's worth mentioning a couple of ingenues who were hot prospects a year ago -- Coco Vandweghe and Asia Muhammad. They remain prospects today, though not quite so hot.

Both have spent the year playing the bush leagues -- $25,000 and $50,000 ITF tournaments. Vandeweghe got into three regular WTA matches and won one. She reached the quarters of a $50,000 event in Troy, N.Y., earlier this month. But she's going to be 18 on Dec. 6. If she is going to make a move on a tour where players peak earlier than the men, it has to come in 2010. She began the year at No. 405 and is now 343.

Muhammad is 18 already and didn't get into a regular WTA match this year. She's gone from No. 402 in January to No. 378 today. Not an impressive improvement. She reached the quarters of one ITF $50,000 event, in Las Vegas.

Time is still on the side of both Coco and Asia. It won't be nearly so a year from now.

As for Oudin, she's still a classic work in progress. She made a lot of fans at the U.S. Open, where she upset Elena Dementieva, Maria Sharapova and Nadia Petrova to reach the quarters, before losing to Caroline Wozniacki. She then took some time off and flew to the Orient, where she won one of three matches in Tokyo and Beijing. She'll be working hard this off-season to make her shoulders more flexible, which should allow her to add some very much-needed pace to her serve.

She can't keep spinning in 78 mph seconds and depending on her quickness to keep opponents from taking control of her service points.

Today, the U.S. has five women ranked in the top 100 -- Serena at No. 2, Venus (4), Oudin (47), Craybas (77) and King (78). That's the same number we had in January, when Serena was at No. 2, Venus (6), now-retired Lindsay Davenport (36), Mattek-Sands (39) and Craybas (66).

Oudin has jumped 130 spots and King 51 to reach the top 100 this season.

A year ago the U.S. had nine women's titles -- all from Serena, Venus and Lindsay. This year, just four -- two each for the sisters. But three of those four titles are Grand Slams and that keeps the U.S. very much in the elite of the women's game.

But for those who worry about the future, there will be a time of course when the sisters retire, possibly together. It is hoped by the USTA that Duval and Vickery, who might be 16 or 17 by that time, will become more obvious top-10 players.

Both are doing very well in junior play, though there again there is a paucity of U.S. talent. Discounting No. 5 ranked ITF junior Oudin, who no longer plays junior events, the highest ranked U.S. girl in the juniors is No. 59 Christine McHale of Englewood Cliffs, N.J.

Charles Bricker can be reached at bricker@tennisnews.com