It's been mentioned in a backhanded sort of way during big bore kit discussions. Compression pressure bleeds off at lower engine speeds, allowing higher compression ratios with lower octane fuel. At high engine speeds where the cams are designed to give optimum power, the effective compression is higher that the actual ratio because the cams are packing more air into the cylinder. This works well because the engine is turning fast enough that the ignition lights off the mixture before it heats up enough to detonate.
