The first is the longevity and continuity of my high-level performance. The second is the bond with my teammates, with our chemistry on the pitch, which is one of the most beautiful ways of working and playing together.

And then in 1974 I started to work on phosphorous chemistry which is the area of which I’m most proud as it turns out. I’m most proud of my work on carbon phosphorous chemistry.

With family, that's the main thing. That's why you do things. Being a bit older and seeing my kids grow into teenagers, I'm helping them grow up in life. That's what I'm proud of - that's what I do everything for.

I have always thought of him as the leader in all of this so … but I take great pride in him because he was my PhD student so I take a lot of pride in having sort of at an early stage influenced him, and in this whole field of market design and auction design. This of course, by the way, is the third of my students who’ve won Nobel Prizes.

As many of you know, the past three years have presented me with challenges in the form of injuries and surgeries. I've worked hard to return to full competitive form. But I also know my body's capacities and limits, and its message to me lately has been clear. I am 41 years old. I have played more than 1,500 matches over 24 years. Tennis has treated me more generously than I ever would have dreamt, and now I must recognize when it is time to end my competitive career.

Of all the gifts that tennis has given me over the years, the greatest, without a doubt, has been the people I've met along the way: my friends, my competitors, and most of all the fans who give the sport its life.