How does captain america know he'll get back his shield?

When Captain america throws his shield it almost always comes back to him and i wanted to know does he calculate in his mind about how it comes back or something or does it have some kind of boomerang effect. Does he constantly look at everything in the area to see if he can make the shot and get his shield back to him kinda like from that Sherlock homes movie? My questions are

1. How does captain america's shield always come back

2. If he is calculating it then wouldn't that make him a super genius

3. If he is a super genius is this a result of the super soldier serum

(READ THE OP)

He is probably just that accurate. Ive seen him lose it on occasion

He sees through his eyes..

@dagmar_merrill: Don't be a smart ass

He sees in black and white because he is old

1. its not flat and he throws at an angle that will ricochet back
2. not really just highly skilled. is every marksmen a super-genius?
3. he possibly is a super-genuis due to the serum. not in the scientific or mathematical sense but that his thinking process is probably clearer, faster and more efficient then normal humans

@kasino: Makes sense

Every day he wings it!

@gojira2014: I wish this were true

I see no reason why number 3 couldn't be true in the way that it was explained here.

1. He knows where it's going to bounce
2. Kinda
3. Yes. It's a combination of his skill, experience and his enhanced mind.

Cuz Comics.

Enhanced spatial awareness.

@kasino: The SSS increase his mental speed and spatial awareness(maths requires spatial awareness and logic) and ability to absorb knowledge at a faster rate than a normal human but it did not increase his other aspect of intelligence such has logic, abstract thinking and creativity.