It's all about using a plug with the correct heat range!
I use NGK B6HS in the summer (colder plug) & B5HS in the winter (hotter plug).
If the plug is too hot?, it can cause pre-ignition; & if it's too cold?, it can foul with unburned gas & oil.
For someone like Baird who runs a heavily modified engine (that will run hotter), he would have to use a colder plug to prevent pre-ignition.