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.

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 tried-and-true metrics and fundamental analysis to find companies that they believe are undervalued at their current share price levels.

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 The Hanover Insurance Group (THG Quick QuoteTHG - Free Report) . THG is currently sporting a Zacks Rank #2 (Buy), as well as an A grade for Value. The stock is trading with P/E ratio of 10.86 right now. For comparison, its industry sports an average P/E of 26.05. Over the past 52 weeks, THG's Forward P/E has been as high as 13.52 and as low as 10.12, with a median of 11.25.

Value investors also use the P/S ratio. The P/S ratio is calculated as price divided by sales. This is a preferred metric because revenue can't really be manipulated, so sales are often a truer performance indicator. THG has a P/S ratio of 1.02. This compares to its industry's average P/S of 1.17.

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