A hard corner is technique played by a cornerback where he has flat responsibility and will likely be jamming the receiver and funneling him toward the middle of the field.
Note that a cornerback playing up across from the receiver is not necessarily a hard corner. The key to playing a hard corner technique is to remain close to the line of scrimmage playing the flat as opposed to back pedaling to an intermediate or deep zone. Hard cornerbacks almost always have safety help toward the center of the field, so they will try to prevent an outside release from the receiver. The opposite of a hard corner is a soft corner.
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