This is a basic engine theory question - please don't flame me if this sounds stupid.

Using a JRSC on a Type R (but this shouldn't change the answer):
So ping/detonation occurs when fuel/air mixture ignites itself either due to high temperature, high pressure, lean mixture, etc. prior to when the plug is timed to trigger that ignition.

So, my question is, if when using a higher than spec boost, the instructions are to add retard to the timing (i.e. spec is 16°BTDC, recommendation is 7°BTDC with 92 octane @ 5lb boost). My understanding is that this is to eliminate ping/detonation. But if the fuel/air pressure/temperature is going to self-pre ignite anyway, how does delaying the plug spark till after that event help?

Again, please be nice - just getting started here.

Thanks