Don't have as much time to research stocks as you'd like? That doesn't mean you have to settle for index fund returns. Value investor and Columbia professor Joel Greenblatt shares his "Magic Formula" for market-beating stock returns in his book The Little Book That Beats the Market.

The Magic Formula ranks stocks based on two factors: how cheap the stock is relative to the company's earnings, and how profitable the company is. Greenblatt suggests buying the top-ranked stocks, holding them a year (give or take a week for tax purposes), and then reinvesting in the latest batch of top stocks.

That may seem too simple. But Greenblatt backtested his formula on the 3,500 largest U.S. stocks, excluding utilities and financials, and he found that the top 30 stocks generated an annualized return of 30.8% from 1988 through 2004, compared with 12.4% for the S&P 500 Index (excluding trading costs and taxes). Moreover, when he ordered those stocks by ranking and split them into 10 groups of 350 each, he found that the higher a group's ranking, the higher its returns.

A Foolish twist
I decided to apply a Foolish twist to the Magic Formula approach by calling upon the Motley Fool's CAPS Community. Greenblatt observed that fundamental research by knowledgeable investors improved upon his approach, so why not use the wisdom reflected in CAPS scores to refine a list of stocks that do well according to the Magic Formula criteria -- and hopefully sidestep some value traps? 

To do so, I ran a stock screen looking for U.S. stocks with high returns on capital of at least 15% as well as relatively high operating earnings yields of 7% or more. Like Greenblatt, I filtered out utilities and financials, as well as stocks with market caps less than $500 million or share prices less than $5. After ranking the results, I then selected only stocks that earned a top five-star rating on CAPS. Here are the seven highest-ranking stocks that passed the screen:

Stock

Profitability (RoC)

Earnings Yield (EBIT/EV)

Market Cap (Millions)

TeleNav (Nasdaq: TNAV) 33% 17% $632
Alliance Resource Partners (Nasdaq: ARLP) 23% 14% $2,580
National Presto Industries (NYSE: NPK) 20% 17% $677
Joy Global (Nasdaq: JOYG) 27% 10% $8,767
Alliance Holdings (Nasdaq: AHGP) 22% 11% $2,685
Western Union (NYSE: WU) 24% 10% $12,418
Philip Morris International (NYSE: PM) 32% 8% $120,078

Sources: Capital IQ, a division of Standard & Poor's; and Motley Fool CAPS as of 6/16/11.

Patience is a virtue
The Magic Formula is designed for the long haul, and it's not for the faint of heart. In Greenblatt's backtest, it underperformed the market in one of every four one-year periods and one of every six two-year periods. Over three-year periods, though, it beat the market in 19 of every 20 periods tested (that's 95% of the time).

Stocks that score well under the Magic Formula criteria have the potential to significantly outperform the market, but its mechanical approach sometimes gives high ranks to value traps. Looking to CAPS to refine those results could help you avoid value traps while building a portfolio of inexpensive stocks in highly profitable companies.

Interested in these high-scoring stocks? Add them to My Watchlist, our free, personalized stock-tracking service, now:

Fool contributor Cindy Johnson owns shares of TeleNav. The Motley Fool owns shares of National Presto Industries and Philip Morris International. Motley Fool newsletter services have recommended buying shares of Philip Morris International, Alliance Resource Partners, and Western Union, as well as writing a covered strangle position on Western Union. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy