No one could give you the exact number.
Thousands, maybe tens of thousands would play the game across the nation.
So imagine how hard it would be to be one of the 64 best in your age group.
Just 64 players from that incredible pool of talent got to compete at the National Hardcourt Championships in December.
And Isabella Crossman was one of them.
She competed against the top 12 and under girls in the country, and 10 international competitors, with the top players having not only tennis experience in hand, but being a year older than bottom age Isabella.
Though she wasn’t going to let this get in her way.
She took to the Melbourne Park precinct in mid-December, having already played a key role in team Victoria’s Margaret Court Cup charge at the same venue just days before. Isabella opened her tournament in singles play against Mahina Warren, with Isabella flying through her opening match 6-0, 6-1.
But there would was respite in the tournament for Isabella, with her second round match pitting her against the sixth seeded player for her age group.
Western Australian Rhea Makesar held the year advantage, as well as being ranked more than 100 players higher.
Isabella was overmatched in the opening set of play, going down 6-0.
But she was able to make a strong charge in the second set, taking Makesar to her limits in a 7-5 set, though the result would end Isabella’s main draw campaign.
She moved to the consolation compass draw, where she competed in a further three matches to complete her tournament.
Teaming with fellow Victorian Mahi Khore, Isabella took the eight seed into the doubles tournament.
Two straight-sets wins — 6-0, 6-3 and 7-5, 6-4 — saw the team advance to the third round, where they took on second seed Ayuna Nakazato and Mayu Crossley of Japan.
The number two seeds proved to be too good on the day, winning 6-0, 6-0 to knock Isabella and Mahi out of the tournament.
Just days before, Isabella had a strong showing as a member of team Victoria.
She started the tournament against Tasmanian Brooke Miller, winning 4-6, 6-2, 10-6, before teaming with National championship partner Mahi Khore to defeat Miller and Alicia Dale 6-2, 7-5.
Against NSW opponent Anna Bishop, Isabella dominated in a 7-5, 6-1 victory, before teaming with Zara Lumanovski against NSW pair Rianna Alame and Chanel Awkar for a 6-3, 2-6, 10-7 win.
Victoria ended the tournament in fourth spot, after losing the third place playoff to Queensland.