sentences:  They follow value investing rules set up by Graham and Dodd.Buffett starts the article with a rebuttal of a popular academic opinion that Graham and Dodd's approach ("look for values with a significant margin of safety relative to [stock] prices") had been made obsolete by improvements in market analysis and information technology.If the markets are efficient, then no one can beat the market in the long run; and apparent long-term success can happen by pure chance only.