 Welcome back to Tennis Talk, my name's Cam Williams and with Carlos Alcárez winning the US Open last week and becoming the world number one, he's actually broken a very long standing record, a record that's lasted 20 years, becoming the youngest world number one of all time. Let's go check out the ATP's youngest world number ones of all time. Starting at number five we have Andy Roddick coming in at 21 years old and 65 days and he achieved this on November of 2003. So just after he won the US Open in that same year. Coming in at number four is John McEnroe at 21 years old and 16 days and he achieved this in March of 1980 after winning his first slam in 1979 US Open. Coming in at number three is Murat Safin at 20 years old and 298 days. He also achieved this by winning the US Open in the year 2000 and got to world number one of November of that year. So seems to be a running theme here. Coming in at number two is Layton Hewitt at 20 years 268 days, about a month younger than Safin and just like everybody else on this list was achieved at the end of 2001 and around November after he had won both the US Open and the ATP finals. And then of course coming in at number one the only teenager on the ATP to become world number one Carlos Elcaraz, 19 years and 196 days about a year younger than Layton Hewitt did it back in the year 2001. Of course this was after winning the US Open last week. So there you have it. That is the record breaking run of Carlos Elcaraz not to mention he's smashed the record by over a year beating Layton Hewitt's record but you've got some massive champions there. And if you notice the theme they all became world number one after winning the US Open. Let me know down in the comments below. How long do you think Elcaraz can be world number one? Because of course Rafa's not far behind. Rafa has a lot of points he can make up in the rest of the season. Also Casparud at number two in the world Djokovic is coming back. Medvedev's looking for number one again. Who do you reckon is going to be world number one by the end of the year and can it be Carlos Elcaraz?