How about 'contrary thinking'? Probably you've heard this 'A million-to-one chance succeeds nine times out of ten'?
How to guess? There are not too many abandoned coins at Cryptsy with market cap less than $100,000.
Sometimes one or another crypto allows to sell it significantly higher. Other coins could be waiting in portfolio till their time come. If 1 from 50 coins makes 5,000% profits (it happens) then 50 coins portfolio total value adds more than 100%, even if other 49 coins stagnate, not bad.
'Investor' doesn't mean 'trader', 'trader' doesn't mean 'manipulator'. 'Whale' doesn't mean 'dev'. 'Devs' or 'whales' don't mean 'manipulators' or 'traders'.
Altcoin world has a lot of players, a lot of interests, and it's pretty unique system. It's interesting. More interesting, than just BTC, or LTC.
To invest money into a 'good project'? It's not simple to find one.