Value investing is about estimating and valuing future cash flows, not about how low a Price to Book or a Price to Earnings ratio is for a stock.
As Charlie Munger pointed out, all investing is value investing, in the sense that you expect your investment to be at a higher value when you sell it. This makes investors jobs much harder.
Read: Buffett and Munger's problem with value investing
and, this is not related but another Food for though