Serena vs. Venus: Williams sisters' US Open showdown by the numbers

With the second and fifth seeds still in the tournament, Williams may have to face either Simona Halep or Petra Kvitova to sweep all four Grand Slams in 2015, but first she'll have to face her big sister Venus in the quarterfinals on Tuesday night. How

Two of the most dominant women's tennis players in history, who also happen to be sisters, will meet for the 27th time Tuesday night at the US Open quarterfinals. Combined, the Williams sisters are a staggering 151-22 (83-9 for Serena; 68-13 for Venus

Cilic leads two sets to one, but if Tsonga can find a way to force it to a decider then it's unlikely the sisters will start on schedule. While we're waiting, here's a must-watch feature on Venus and Serena from when they were 12 and 11 years old

Cilic leads two sets to one, but if Tsonga can find a way to force it to a decider then it's unlikely the sisters will start on schedule. While we're waiting, here's a must-watch feature on Venus and Serena from when they were 12 and 11 years old

Congratulations Venus Williams! Venus graduated with an Online Business Degree from Indiana University East under a partnership with the Women's Tennis Benefits Association.