Every long-term investor has their favorite Buffett quote. Mine is, "Wait for a fat pitch and then swing for the fences."

Simple, succinct, and memorable. I'm convinced it's the best investing advice Buffett has ever doled out! That's because it pulls together all the wisdom from his other top quotes.

Just below, I'll let you in on a fat-pitch stock you can own right now, but first let me explain the idea behind a fat pitch and some pointers on how to identify one.

"Hitting is fifty percent above the shoulders"
Buffett didn't invent the fat-pitch idea. He borrowed it from baseball legend Ted Williams, a two-time Triple Crown and two-time American League MVP winner who holds the record for having the highest career batting average for players who hit more than 500 career homeruns.

What's more impressive is that he retired in 1960. So even today's steroid-injected players haven't been able to top his record. Which means Williams is an expert on hitting if there ever was one.

Williams revealed his secret in the book The Science of Hitting. Each time he stepped up to the plate, he divided the strike zone into 77 squares. And rather than randomly swing, Williams swung only when the ball was in his favorite squares. If the pitch wasn't in his sweet spot, he just let it fly on by.

As his 50-year record shows, it's not an easy strategy to replicate in baseball.

But the fat pitch is much easier for individual investors
That's because, with investing, there's no limit to the number of poor pitches you can let fly by. There are no called strikes. Which means you can wait as long as it takes for the perfect pitch to come. And when it does, you make your move to profit big time. Which is exactly what Buffett has made a career of doing -- and what you should be doing right now.

Here are three criteria Buffett looks for in a fat pitch. Read them and then I'll share with you that fat-pitch stock I promised.

1. Management
Buffett looks for managers who are obsessed with the long-term performances of their businesses. This is more than just a passion for helping a stock rise, or else Buffett would have bought out a company like Overstock.com (Nasdaq: OSTK) a long time ago.

Investors like you and I can't always chat intimately with CEOs, but a foolproof way to judge their outlook is by reading the DEF 14A Proxy Statement that public companies file with the SEC. It's where executives' compensation is laid bare. So you're free to decide whether a CEO is milking shareholders for money, or whether she is being compensated for growing the business.

As an example, I would shy away from owning shares of MicroStrategy (Nasdaq: MSTR) because its executive compensation isn't tied closely enough to the underlying business.

Sure, founder-CEO Michael Saylor didn't have a huge cash salary in 2008, as far as executives are concerned (just $787,500), but his total compensation package came to more than $2.7 million.

What accounted for the difference? Items like $128,995 for using a company vehicle, and $83,088 in tax reimbursements for that vehicle; $26,699 for an "Entertainment Event" ("parties, outings or similar entertainment events"); and $19,493 in tax reimbursements. He also got a $1.4 million bonus.

All this while his company's net income continued its long-term drop -- from $168 million in 2004 to just $42 million in 2008. Free cash flow has also declined.

Compare this to a founder-CEO like Jim Sinegal of Costco (Nasdaq: COST), who voluntarily forfeited a $200,000 bonus in 2006 because of a mere "imprecision" in the company's stock-option granting process.

They say that actions speak louder than words. Well, the actions of these executives make clear who is a more shareholder-friendly manager. Of course, even the best manager can't help a poor business, which brings us to the next factor.

2. Moat
Buffett seeks out companies that have a "formidable barrier" ensuring that competition can't easily take them down. This explains Buffett's fascination with companies that have strong brands, like Coca-Cola (NYSE: KO) and American Express (NYSE: AXP). Both companies' brands are well-known and trusted, and were built over decades.

Even though Coca-Cola's newest competitors -- like Hansen Natural (Nasdaq: HANS) -- are growing their customer bases at mind-boggling rates, they aren't close to possessing the reputation that has taken Coca-Cola more than 100 years to build.

But of course, investing all comes down to the price you pay. Which leads to the next criterion.

3. Smart value
 Buffett also says, "Price is what you pay. Value is what you get." You can have a world-class manager with a strong moat, but if you pay a lofty price for it, your returns will suffer.

This is why companies like salesforce.com (NYSE: CRM) aren't fat-pitch stocks. Sure, it has a brilliant founder-CEO and was a first mover in the sphere of cloud computing, with a strong reputation, but priced at 107 times earnings and 41 times free cash flow, it's not a cheap investment.

So now you're probably wondering ...

What is the fat-pitch home run stock?
The fat-pitch stock I've promised you is a company that meets all the criteria I just outlined. And that stock is Morningstar.

Its CEO, Joe Mansueto, founded the company in 1984. It has a strong moat -- a virtual monopoly on information technology and research used by analysts and financial advisors all over the world. And given its strong financial performance, the stock is pretty cheap -- trading for around 25 times free cash flow.

There's even a kicker. Morningstar has built up so much data that it has the capability to enter all sorts of new fields. Not only could it delve further into asset management, but it recently announced plans to enter the debt-rating industry, just to name a few.

Where to get even more fat-pitch stocks
To take advantage of the many fat pitches the market is tossing your way, I invite you to try David and Tom Gardner's Motley Fool Stock Advisor free for 30 days. These are the brothers who founded The Motley Fool, and they've developed an enviable track record of uncovering fat pitches -- with much success. Their average pick is beating the market by more than 50 percentage points.

To check out other fat pitches they've recommended, I invite you to give Stock Advisor a try. To learn more, click here now.

 Adam J. Wiederman owns shares of Costco and Morningstar, which are Motley Fool Stock Advisor recommendations. The Motley Fool also owns shares of Costco and Morningstar. salesforce.com and Hansen Natural are Motley Fool Rule Breakers picks. American Express, Costco, and Coca-Cola are Motley Fool Inside Value recommendations. Coca-Cola is also a Motley Fool Income Investor pick. To learn all about our fast-pitching disclosure policy, click here.