Here at Zacks, we focus on our proven ranking system, which places an emphasis on earnings estimates and estimate revisions, to find winning stocks. But we also understand that investors develop their own strategies, so we are constantly looking at the latest trends in value, growth, and momentum to find strong companies for our readers.Considering these trends, value investing is clearly one of the most preferred ways to find strong stocks in any type of market. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.On top of the Zacks Rank, investors can also look at our innovative Style Scores system to find stocks with specific traits. For example, value investors will want to focus on the "Value" category. Stocks with high Zacks Ranks and "A" grades for Value will be some of the highest-quality value stocks on the market today.One company value investors might notice is Old Republic International (ORI). ORI is currently sporting a Zacks Rank of #2 (Buy), as well as an A grade for Value.Value investors also love the P/S ratio, which is calculated by simply dividing a stock's price with the company's sales. This is a popular metric because sales are harder to manipulate on an income statement, so they are often considered a better performance indicator. ORI has a P/S ratio of 0.92. This compares to its industry's average P/S of 1.2.Finally, investors should note that ORI has a P/CF ratio of 4.70. This metric takes into account a company's operating cash flow and can be used to find stocks that are undervalued based on their solid cash outlook. ORI's P/CF compares to its industry's average P/CF of 14.33. Over the past year, ORI's P/CF has been as high as 141.88 and as low as 3.92, with a median of 15.14.Value investors will likely look at more than just these metrics, but the above data helps show that Old Republic International is likely undervalued currently. And when considering the strength of its earnings outlook, ORI sticks out at as one of the market's strongest value stocks.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Old Republic International Corporation (ORI): Free Stock Analysis Report To read this article on Zacks.com click here.