Values for zNear/zFar Correction

[zephyrsurfer]

I wasn't sure where to post this but I'm trying to fix Captain Tsubasa.

How were the values for the Custom Projection Hacks for games like Sonic and the Black Knight arrived at?

One of the presets in earlier dolphin builds fixes the intro video but not the rest of the game.

Suggestions on how I'd go about fixing this. Thanks.