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, value investing is easily one of the most popular ways to find great stocks in any market environment. Value investors rely on traditional forms of analysis on key valuation metrics to find stocks that they believe are undervalued, leaving room for profits.

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 to watch right now is Alliance Resource Partners (ARLP Quick QuoteARLP - Free Report) . ARLP is currently sporting a Zacks Rank #1 (Strong 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 13.36. 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 figure highlights a company's operating cash flow and can be used to find firms that are undervalued when considering their impressive cash outlook. ARLP's P/CF compares to its industry's average P/CF of 9.37. ARLP's P/CF has been as high as 6.90 and as low as 3.82, with a median of 5.55, all within the past year.

These are only a few of the key metrics included in Alliance Resource Partners's strong Value grade, but they help show that the stock is likely undervalued right now. When factoring in the strength of its earnings outlook, ARLP looks like an impressive value stock at the moment.