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.

Considering these trends, value investing is clearly one of the most preferred ways to find strong stocks in any type of market. 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 The Hanover Insurance Group (THG Quick QuoteTHG - Free Report) . THG is currently sporting a Zacks Rank #1 (Strong Buy), as well as a Value grade of A. The stock holds a P/E ratio of 10.86, while its industry has an average P/E of 26.25. THG's Forward P/E has been as high as 13.52 and as low as 10.12, with a median of 11.25, all within the past year.

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. THG has a P/S ratio of 1. This compares to its industry's average P/S of 1.19.

These are only a few of the key metrics included in The Hanover Insurance Group'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, THG looks like an impressive value stock at the moment.