do you guys know how long the B2 session was? because everyone always says the alpha kids are older than the beta, and they were when their session started, but when the betas arrive in the alpha session, the betas are sixteen? and I didn't think the alpha session was that long?

The Alpha kids started playing when they were 15 and spent approximately six months in the game and within that time they all had a birthday and turned 16. The Alpha kids are not older than the Beta kids, they are the same age.