Dual points are "interesting", but for most people cause more trouble keeping them setup properly than any benefit they provide.
Increased dwell: the amount of time the coil is "charged up" with low voltage, the more "charge" or "energy" is stored in the coil the better. When the points (electronic trigger or whatever you might have) break the low voltage circuit all that "stored energy" in the coil winding collapses and "induces" a high voltage energy burst into the center solid core of the coil. This high energy boost with a "point type system" and a "decent coil" is around 15 to 20 thousand volts. All that from a 12 volt momentary charge!
Electronic ignition is a better "switch" than points could ever hope to be. A "clean" ON-OFF signal. Points tend to "arc" when they open/close, so it's not a clean break/make deal. The "burst" of energy is thus somewhat degraded.
In addition, an electronic "switch" can increase the "dwell" much longer than points ever could. Clean break, more dwell, BIGGER bang! Figure 30 to 40 volts AND reliable at high rpm!
So what? If the spark plug will "fire" with 10K volts, why do you need 40K volts? You might not! High compression, engine timing, lean fuel air ratios, high rpm are all things that affect the voltage required to "fire" the spark plug. Thats why some motors need it, some don't!
Ernie
That was fun, you know how it is to find someone that even wants to talk about "points" these days???
