Andre Agassi and Steffi Graf have an 8-year old son and a 6-year old daughter. Graf, is arguably, the greatest women's tennis player of all time. Agassi is easily in the top 5 for men.
Roger Federer and his wife Mirka recently had twin girls as well. Federer, is arguably the greatest men's tennis player of all time. Mirka also played tennis at the professional level until an injury ended her career.
How cool would it be if these children were the next generation of great rivals? And before you say it's ridiculous, remember that the current top two women's tennis players in the world just happen to be sisters.
Also, what other sports could you see this super-genetic mating happen in? And 100 pts. if you think through why this could never happen in basketball.