JACKSONVILLE, Fla. -- It's a debate a lot of parents face as their child turns five years old, should you put them in kindergarten right away or hold them back a year?

It's a practice called "red-shirting," a term borrowed from sports. The idea is that if parents hold their child back a year, they'll have an advantage in the classroom.

Kindergarten was once thought of as a place for games, arts and crafts, and recess, but teachers say, it's no longer the playground it used to be.

"They're learning so much more a lot earlier now," said Jessica Martinez, a Voluntary Pre-Kindergarten Teacher at Ivy League Academy San Pablo.

In her classroom, there are stations of four year olds learning to write their names, attempting simple math, focusing on letters, numbers, shapes, and colors.

"These days the foundation has to be built before they go to kindergarten," Heather Saintgeorges, the Director of the academy said.

"Letter recognition, upper case and lower case, phonics, math concepts, science. Learning how to socialize, recognize their name," are all things Saintgeorges said teachers recommend students have a grasp of, before entering kindergarten.

"They're putting more and more tests on the kids in elementary school," Martinez said. "Everything is getting bumped to grade level."

So if kindergarten is becoming the new first grade, should parents contemplate holding their child back?

Joyce DeLaGarza waited a year for her daughter Anna to get more socialized. "Maturity wise, she wasn't quite ready," DeLaGarza said. "I talked to a lot of moms about their deciding factor... and every single one of them never regretted it."

What makes a child ready? In Florida, it's the date of September 1st, the birthday cut-off for five year olds.

"What kind of worries me is the parents who look at kindergarten as an all-day, free daycare. and they're putting their kids in as soon as they can," Dr. Lynn Olson, the Director of Elementary Education for Creighton University said.

But many parents can't afford the high cost of daycare, a potential reason red-shirting is more common among wealthy families, which causes many to question if it's even a fair practice.

"My child entering kindergarten, I have the confidence that he is going to be fine," Selena Hodge said. Her five-year-old son, David, is starting Kindergarten this year - on time, she said, thanks to preschool.

"He is great with letter identification," Hodge said. "He's good with his colors now and he's also proficient at writing his name."

While research varies on the benefits of red-shirting, educators seem to agree - a big advantage is an early start.

Four year olds can attend a VPK program for free three hours per weekday. Parents can go to theEarly Learning Coalition to apply for a voucher.