To summarize he believes the main skills in picking a stock correctly are correctly valuing the company (either above or below current appraisals) and being detached from the opinions of others, which will influence your thinking.
The following six paragraphs are all from the article cited above:
"[It] comes about from having an investment philosophy grounded in the idea that a stock is a piece of a business. If you look at it that way, there's no reason to get excited whether some analyst is recommending it or the company is splitting the shares two-for-one, or whatever. The only way to drive the extraneous thoughts out of your mind is to have a philosophy. And for us that philosophy comes from Benjamin Graham and The Intelligent Investor, especially chapters 8 and 20. It's not very complicated stuff."
"It doesn't make any difference what other people think of a stock. What matters is whether you know enough to evaluate the business," he opined.
You should be able to write down on a yellow sheet of paper, 'I'm buying General Motors at $22, and GM has  million shares for a total market value of $13 billion, and GM is worth a lot more than $13 billion because _______________." And if you can't finish that sentence, then you don't buy the stock.
The key is not to be seduced by crazy ideas, but instead just stick to the fundamentals year after year. Academia doesn't get too interested in us -- we're too simple. What would the professors do? A great many of the formulas [they use to analyze securities and markets] are dead wrong. They exist purely to give the intellectual class something to do. We don't do anything just exercise our intellectual proclivity for mathematical formulas.
Instead, if you are a true investor, you should shop for stocks the same way you shop for anything else: Look for sale prices, and never regard falling prices as inherently bad news. Instead, falling prices create the opportunity to buy even more of something that was already worth owning.
In that single sentence Buffett captured the difference between investing and speculating: An investor, like Buffett, wants the price of a stock to fall below the value of its underlying business so he can buy even more and hold for as long as possible.
So to summarize, one wants teams to perform poorly, to have their "stock drop" below their true levels.
Smart man, a lot to learn from him.