Does the acorn cup cover >1/2 or <1/2 of the acorn?

Acorn cup deep, covering 1/2 or more of the acorn

Acorn cup scale tips loosed
Fall leaf color yellow to orange, never red
Black Oak (Quercus kelloggii)

Acorn cup shallow, usually covering less than 1/2 of the acorn

Acorn cup scale tips pressed tightly together
Fall leaf color often red or reddish brown