I don't get it. Why would you split? You choose the most profitable one and stick to it, until you find a more profitable coin, then you switch your entire mining power to it. Now, I remember during the time I was mining that the profitability of certain coins changed all the time, so I had to do a lot of switching but I never split my mining power. Maybe there are legitimate reasons to split but I never did so.
Very interesting answer.
Something I'm trying to figure out: How nigh mining power would you estimate the average miner has? Is there any way not to get the distribution of mining pools but rather an estimated distribution of of individual miners?