Jackie ~

My sense of the use of "dead" in the expression "dead game little sport" is that it means "very, exactly, extremely, precisely."

You have heard the Americanism "he was a dead ringer for his brother" in the sense that the two boys looked exactly alike.

Brits sometimes use it with time, e.g. "the race begins dead on noon" meaning that it will start precisely at 1200.

A man is not revealing necrophiliac tendencies when he says a woman is "dead gorgeous."

The position of twelve o'clock on a flywheel is sometimes called TDC for "top dead center."

Odd, this language of ours.