The proven Zacks Rank system focuses on earnings estimates and estimate revisions to find winning stocks. Nevertheless, we know that our readers all have their own perspectives, so we are always looking at the latest trends in value, growth, and momentum to find strong picks.

Of these, value investing is easily one of the most popular ways to find great stocks in any market environment. Value investors use a variety of methods, including tried-and-true valuation metrics, to find these stocks.

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 stock to keep an eye on is Alliance Resource Partners (ARLP Quick QuoteARLP - Free Report) . ARLP is currently sporting a Zacks Rank #2 (Buy), as well as an A grade for Value. The stock holds a P/E ratio of 9.28, while its industry has an average P/E of 12.90. ARLP's Forward P/E has been as high as 11.04 and as low as 6.67, with a median of 9.31, all within the past year.

Finally, investors will want to recognize that ARLP has a P/CF ratio of 5.83. 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. ARLP's current P/CF looks attractive when compared to its industry's average P/CF of 9.75. Over the past 52 weeks, ARLP's P/CF has been as high as 6.90 and as low as 3.82, with a median of 5.55.

These figures are just a handful of the metrics value investors tend to look at, but they help show that Alliance Resource Partners is likely being undervalued right now. Considering this, as well as the strength of its earnings outlook, ARLP feels like a great value stock at the moment.