While the proven Zacks Rank places an emphasis on earnings estimates and estimate revisions to find strong stocks, we also know that investors tend to develop their own individual strategies. With this in mind, we are always looking at value, growth, and momentum trends to discover great companies.Of these, perhaps no stock market trend is more popular than value investing, which is a strategy that has proven to be successful in all sorts of market environments. Value investors use fundamental analysis and traditional valuation metrics to find stocks that they believe are being undervalued by the market at large.Luckily, Zacks has developed its own Style Scores system in an effort to find stocks with specific traits. Value investors will be interested in the system's "Value" category. Stocks with both "A" grades in the Value category and high Zacks Ranks are among the strongest value stocks on the market right now.One company value investors might notice is BellRing Brands (BRBR). BRBR is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock has a Forward P/E ratio of 21.24. This compares to its industry's average Forward P/E of 25.88. Over the past 52 weeks, BRBR's Forward P/E has been as high as 32.38 and as low as 21.24, with a median of 28.74.BRBR is also sporting a PEG ratio of 0.73. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. BRBR's industry currently sports an average PEG of 2.13. Over the last 12 months, BRBR's PEG has been as high as 2.19 and as low as 0.73, with a median of 1.33.Finally, we should also recognize that BRBR has a P/CF ratio of 11.75. This figure highlights a company's operating cash flow and can be used to find firms that are undervalued when considering their impressive cash outlook. This company's current P/CF looks solid when compared to its industry's average P/CF of 19.71. BRBR's P/CF has been as high as 20.29 and as low as 11.75, with a median of 16.88, all within the past year.Value investors will likely look at more than just these metrics, but the above data helps show that BellRing Brands is likely undervalued currently. And when considering the strength of its earnings outlook, BRBR sticks out at as one of the market's strongest value stocks. Zacks' Top Picks to Cash in on Artificial Intelligence In 2021, this world-changing technology is projected to generate $327.5 billion in revenue. Now Shark Tank star and billionaire investor Mark Cuban says AI will create "the world's first trillionaires." Zacks' urgent special report reveals 3 AI picks investors need to know about today.See 3 Artificial Intelligence Stocks With Extreme Upside Potential>>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 BellRing Brands, Inc. (BRBR): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research