There's a big difference between the best-performing stocks and the best growth stocks, many times one has nothing to do with the other especially in the short-term.
So far 85% of this year's best-performing stocks started the year under $10 and most if not all are unknown and without any great fundamental characteristics. This was the case last year, the year before, and probably will be the case next year. Here is a post from 2013 talking about this very same thing; LINK
You can narrow down the stock universe in many different ways; by market cap, price, fundamentals, PE ratio, above moving averages, or by what works the best within your timeframe. Due to liquidity factors, you might be forced to only deal with stocks that meet certain liquidity, market cap requirements but that does not make them the best stocks, that makes them the best stocks for your own pre-requirement universe.
CHECK OUT THIS VIDEO FROM STOCKBEE OF WHAT WORKS. Believe me, it's worth it.