No. Electricity follows the path of least resistance. It has nothing to do with a split tip or a fancy U groove! The sparkplug does one thing only. It acts as the grounding source for the ignition's electricity and that's it, period, end of story. The only difference with a sparkplug is that there is a gap in the current path. The size of the spark is dictated by the voltage and amperage output of your coil, and the output of your coil is dictated by the saturation (dwell) time of your ignition system. You'll hear claims like, "it made more horsepower" or "I got better gas mileage". Well of course they did! Their engine needed a tune-up or they wouldn't have tried the new plugs in the first place! ANY engine would get better gas mileage and more horsepower after a tune-up! 

What split tipped plugs can do is promote pre-ignition and/or detonation. How? Try this, take a hanger and try to heat it up with a cigarette lighter. Oh yeah, it gets hot, but not hot enough to glow cherry red. Now take a paper clip and heat it up with the same lighter. It gets hotter faster and glows cherry red! It's simple, it takes less heat to heat-up smaller objects. What do you think those tiny little pieces of split tip electrodes are doing in your engine? Now add more compression and heat (like in a race engine) and they act like a dog gone glow plug... detonation... ka-boom! Just about in that order.

Now there ARE things you can do to help the burn in the cylinder with the spark plugs (which actually will increase power), such as indexing them. It's easier to show you how to do this than to tell you, but here's a quick overview so you'll at least get the basic idea. Indexing a spark plug puts the open end of the gap towards the intake valve. This way when it sparks, the ground strap isn't in the way, blocking the flame path. It exposes the open end of the gap to the fresh air / fuel mixture coming through the intake valve and into the cylinder, which helps light the cylinder faster and more evenly. Better burn = more power. There's a little more to it, and like I said, it is easier to show you than it is to write it out. You start by marking the outside of the spark plug with a Sharpie pen in line with the back side of the ground strap. When you screw the plug into the head, try to get the mark to point away from where the intake valve would be. This puts the back side of that ground strap pointing at the exhaust valve or the back side of the combustion chamber, which in turn points the open-end of the gap at the intake valve and into the open area of the cylinder for a clean, unobstructed flame path. They actually make special crush sleeve "washers" that go onto the spark plugs so you can snug the plug up, yet continue to turn it to "index" the plug to where you want it.

Obviously heat range has a little to do with how a plug fires too, but that subject is always a mystery to many people. Many guy's run way too cold of a plug in their performance engines because "their buddy" told them to. I always get a kick out of that. If I had a nickel for every time I heard someone say "my buddy told me to do that" for something that totally didn't work, I'd be a millionaire! Anyway, cold plugs don't retain enough cylinder heat to burn off deposits and they foul quickly, thus making your engine run like crap. A hot plug runs cleaner because nothing can stick to it. When you clean greasy dishes in your sink, you use hot water to cut the grease, right? Well, spark plugs aren't much different. Now, the wives tale is that a hot plug will make your engine run hot, and that is about as ass backwards as you can get. Hold a new spark plug in your hand. is it hot? NO! So how can something that isn't hot, and that doesn't create heat make your engine run hot? It can't. The cylinder temperature inside your engine heats the plug up, not the other way around. All a hot or cold plug means is how hot the core temperature (or running temperature of THE PLUG) will be. If you run too hot of a plug, it will allow it to retain too much heat and it will begin to melt off the electrode, thus causing the engine to misfire. The trick is, you want the hottest plug you can possibly run WITHOUT melting off the electrodes.

Now, a cool trick for nitrous and blower guy's is when you run a plug that is on the hot side, you can actually use the plug as a "safety fuse". In other words, if your plugs run just under the melting point, then if you have the misfortune of leaning the engine out, (THE worst thing you can do to a nitrous or supercharged engine), it will increase the plugs core heat and melt off the electrode, thus causing the cylinder to not fire anymore. No more fire = no heat. No heat means no lean-out melt down. Obviously it takes time and testing to figure out exactly what to run, but these tips give you some good ideas and starting points anyway.