[TheGuardian]

I have to ask because I haven't seen anyone say anything about it. Are the more prominent scratches Radial (going from middle-to-edge of disc) or Circular (Following the spin of the disc) Circular scratches are what cause the most problems because of the laser's tracking while reading the disc. Since those scratches follow the spin of the disc the laser basically gets derailed because it deflects off the scratch and moved to another point in the data which doesn't coincide with what it just read, so it tries over and over to read that point. It won't be able to hit that section so it won't be able to progress. Radial scratches don't deflect the laser that long because it's more like a speedbump, if you get it small enough the laser will deflect for just a very small fraction of a second and won't lose much (if any) data from reading the disc.

Deep circular scratches are what ruin CDs for the most part. It's very hard to fix them without grinding down. This is also why the CD grinding tools you see have a grindwheel that rubs on the disc from the center to the rim instead of a plate that just sits on the disc and grinds it all at once by spinning them opposite of each other.

(I know it's like a month later but I used to repair discs myself all the time and the topic caught my eye. after reading thought maybe I would share that piece of info so more people can understand what's happening and why certain scratches can ruin a game when another can be scratched to hell and still work fine)