Battle Chess by Interplay used a manual look up for it’s copy protection.

This is the screen to enter the code from the manual. If you get the codes incorrect you goto a screen of the game board with no player pieces.

Here is the Off Disk Copy Protection sheet: Battle_Chess.txt

Grave Yard is a different kind of football game.
For the disk copy protection you are asked for a STAT out of the manual.

Click HERE for a Text file of the STATS you need – Grave Yardage