There are too many ICOs nowadays to deeply analyze them all. There have been some articles discussing 2 opposed strategies: “Spray & Pray” versus “Cherry Picking”.
https://blog.bitmex.com/spray-and-pray-the-ico-investment-strategy/
http://whalesfriend.com/ico-strategy/
Maybe the best strategy is to eliminate only the very worst and invest in everything else.
In the end investing in an ICO stays a gamble. Even a good team with a innovative idea can sometimes fail.
All you can do is research as much as possible about the ICO you are interested so I am more the fan of the "Cherry Picking" strategy.
You appear to contradict yourself. If investing is a gamble, wouldn't it be better to spray your chances as widely as possibly? You said it yourself, an ICO may look good according to your research yet still fail sometimes. Therefore research is not a completely reliable strategy. I wholeheartedly agree “Spray & Pray” having a better chance is counter-intuitive though.