In iPhone 6 simulator, UIImageView doesn't go all the way down

I'm using the following code for iPhone 6

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone){

if(([[UIScreen mainScreen] bounds].size.height==667.0f) &&([[UIScreen mainScreen]
bounds].size.width==375.0f)) {

My code for ball going to end of bottom of screen and then regenerate back at top of screen...

if(ball.center.y >666){
ball.center=CGPointMake(ONE.center.x, -30);

In iPhone 6 simulator, the farthest the ball goes down is ball.center.y >585 and only then it regenerates. But how come it doesn't go all the way down to ball.center.y >666?

UI_USER_INTERFACE_IDIOM() works well for iPhone 4s, iPhone 5's as well. (Not using Auto Layout)