I'm too lazy to search my old post, but two seasons ago I played a couple of games with another german manager. We had everytime the same line up and the same enthusiasm. We tried several GDPs, like corret guess in pace and focus and completely wrong guess in both.
To make it short:
Basic defense: 100%
Both right (focus+pace): 110%
Both wrong (focus+pace): 90%
Edit: (255898.8)
I'm late to this thread again, but the 110% matches about precisely what I found as well, though mine was just based on some modified CoachParrot predictions rather than the same lineup twice. Still, when I don't have a blowout, the predictions are generally spot on, so I've been going with the 10% value myself for estimation purposes.