Idon’t watch a lot of tennis, but Wimbledon always grabs my attention for two reasons: Roger Federer and the Williams sisters.

While Federer has ruled men’s tennis most of this decade, Venus and Serena Williams have done the same with the women. The past weekend showed the end of their reigns is nowhere in sight.

On Saturday, Serena Williams beat Venus in straight sets to capture her 11th Grand Slam and third Wimbledon title (her first in six years) and avenged last year’s loss to her elder sister.

Not to be outdone, Federer made history a day later by earning his sixth Wimbledon title in seven years and a record 15th Grand Slam with a grueling five-set marathon against a very determined Andy Roddick.

Wimbledon has been Federer’s and the Williams’ personal playground. At least one of the Williams sisters has appeared in nine of the last 10 finals. They have eight titles between them, with Venus’ five ranking behind only Martina Navratilova (nine), Steffi Graf (seven) and Billie Jean King (six) on Wimbledon’s all-time wins list. Federer’s run of dominance at the All England Club hasn’t been as long, but it has been just as strong.

Venus and Serena Williams are the greatest sibling rivalry in sports.

History will show that Serena is the better of the two because of her 11-10 overall record against her sister, including a 6-2 edge in Grand Slam finals. Serena also has four more Grand Slam singles titles than Venus, and currently owns three of the four major championships.

But Venus’ greatness should not be diminished by the defeats to Serena. Venus may be the second best player in the Williams home, but she is still better than any other woman in the world. That was proven in the Wimbledon semifinals with her 6-1, 6-0 demolition of Dinara Safina, whose world No. 1 ranking has more to do with her busier schedule than talent.

No matter what the rankings say, the Williams sisters are the undisputed queens of women’s tennis. It would be easy for them to walk away from the sport. They have proven to be the best players of their generation. Both are financially secure for the rest of their lives and, unlike most players, they were smart enough to build careers outside of tennis. But they are still here and going strong.

Women’s tennis owes them a debt of thanks for sticking around because the sport needs them more than they need it.

Federer has kept men’s tennis interesting with his brilliant play. Now that he has surpassed Pete Sampras in Grand Slam victories, some people want to anoint Federer as the greatest men’s player ever. But let’s not be a prisoner of the moment.

Can anyone honestly say that Federer is better than Sampras or Bjorn Borg or Rod Laver? Each era is so different that it’s hard, if not impossible, to make an accurate judgment.

Federer has the 15 Grand Slam titles on his side, but Laver might have exceeded his 11 titles had he not been barred from competing for five years after turning pro in 1963. He also won all four major tournaments in one calendar year in 1962 and 1969. Don Budge (in 1938) is the only other player to do it once.

Still, you have to give Federer his due. Who knows how many more Slams he’ll add to his bulging trophy case? That will depend on the health of Rafael Nadal, who couldn’t defend last year’s Wimbledon title due to a knee injury.

When Nadal does come back, he better be on top of his game because Federer sure is.