MSD distributor guru

Ah, the endless "dyno vs seat of the pants" setups.

Completely different results, dyno loves excessive timing, and jetting, seat of the pants makes the engine run right.

Enjoy the dyno delusion, win that dyno race, it is real world, to some that don't have anything else to attain.
Any theories as to why engines on dynos like excessive timing and fuel for most power? Is it like find the best timing on the dyno then subtract x amount or does it change the shape of the curve more and want less or more timing in a certian area? Does this apply to both engine and chassis dynos? Does this hold pretty much true for all engine combinations or just certian combinations or applications. Thanks in advance.