HERAKLION (2015 FIBA U19 World Championship) - A jersey number is often something special to an athlete. Their father may have worn it when he played or they always had that number growing up. Or it was the number of their favourite player. 

For the first time this summer, FIBA is allowing players to wear any number they want in national team competitions - breaking away from the previous regulation where teams could only have numbers 4 to 15.

And two of the 16 teams at the 2015 FIBA U19 World Championship have used the opportunity to wear different numbers. 

Iran have three players sporting non 4-to-15 jersey numbers while Egypt have two such players. 

"I wear number 17 in my team in the Iranian league so I asked them if I could wear it here and they said there is no problem," said Iran guard Dro Der Ghokasian.  

"I'm happy that I can wear my own number, the number I love. I have always worn it and my uncle has worn it too."

Iran guard Amirhossein Azari is wearing number 20 in Crete, because 20 is the best grade in schools in Iran. 

"That is my grade average in school and I want to be the best," said Azari.

The third Iranian to don a different number on his jersey is Mobin Sheikhi with number 19.

"I am one of the youngest players on the team and it's an U19 tournament so that's why I chose it. It's really great to be at this U19 World Championship," the 18-year-old Sheikhi said.

"I feel a lot of freedom to wear whatever number we want. There are no limitations on us." 

He added: "More players will do this in the future."

Egypt have two players who have chosen different numbers with point guard Mohamed Mohamed wearing No. 2 and Esam Mostafa - the youngest player at the tournament at 15 years until August 3 - sporting No. 44.

The other 14 countries in Greece have their 12 players wearing the usual 4-to-15 numbers on their jerseys. And for the United States, the decision to keep the same numbers has to do with the country's legacy.

"We like the idea of there being a legacy with the number," said USA Basketball spokesman Craig Miller. 

"The 4-15 is tradition and we can track who's worn them. A lot of famous players who have gone on to great careers started by wearing a number five or a 12 for example. It’s part of what we try to teach our guys - who came before them and the tradition they have to carry on."

While the 2015 FIBA Americas U16 Championship did not have a single player wear a jersey other than 4-15, the on-going EuroBasket Women 2015 has plenty of examples of players picking different numbers. 

Nine of the 20 teams have at least player using a non traditional number with Hungary leading the way with four players. The most common "new" number is 22 with five players while four players picked 21. The highest numbers are 51 worn by Hungarian Dorina Zele and 92 chosen by Neringa Skadaite of Lithuania. And Sweden's Stefanie Yderstrom wore number 3 at the tournament.

"I picked that number because that was the year in which I was born," said Skadaite.

All told, 12 non traditional numbers were picked by players at the women’s tournament. 

And there are plenty of reasons those players picked their new favourite numbers.

FIBA