So the goal is to find altcoins that will rise bigger in % than BTC to be profitable
The coins that have the biggest % increase are the smallest coins. But obviously this comes with increased risk, because you're betting on something that is earlier on in the development cycle.
In general greater opportunity for profit comes with greater risk. So what you really need to ask, is - how much of a risk am I prepared to take? Would I prefer something that has 50% chance of 10x increase, or something that has 10% chance of 1000x increase but 90% chance of losing everything?
Of course you can make your estimates and then calculate your best option, but it's difficult to quantify the emotional aspect, or to ignore it altogether.
Then there's the question of how knowledgeable you are about the markets and the tech in general, and how well you can identify opportunites and drawbacks. If you are better than most people at identifying which of the smaller coins are a good proposition, then you dramatically increase your chances of success.
The general advice I suppose is to diversify. Put some in the more solid prospects, and some in the more speculative.
profit from it. Just don't be the last one to dump 
