Investors interested in stocks from the Banks - Major Regional sector have probably already heard of KeyCorp (KEY) and Bank of America (BAC). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.The best way to find great value stocks is to pair a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system. The Zacks Rank favors stocks with strong earnings estimate revision trends, and our Style Scores highlight companies with specific traits.Currently, both KeyCorp and Bank of America are holding a Zacks Rank of # 2 (Buy). The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that both of these companies have improving earnings outlooks. But this is just one piece of the puzzle for value investors.Value investors analyze a variety of traditional, tried-and-true metrics to help find companies that they believe are undervalued at their current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.KEY currently has a forward P/E ratio of 11.69, while BAC has a forward P/E of 14.63. We also note that KEY has a PEG ratio of 0.75. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. BAC currently has a PEG ratio of 2.09.Another notable valuation metric for KEY is its P/B ratio of 1.41. The P/B ratio is used to compare a stock's market value with its book value, which is defined as total assets minus total liabilities. For comparison, BAC has a P/B of 1.52.These metrics, and several others, help KEY earn a Value grade of B, while BAC has been given a Value grade of F.Both KEY and BAC are impressive stocks with solid earnings outlooks, but based on these valuation figures, we feel that KEY is the superior value option right now. Zacks’ Top Picks to Cash in on Artificial Intelligence This world-changing technology is projected to generate $100S of billions by 2025. From self-driving cars to consumer data analysis, people are relying on machines more than we ever have before. Now is the time to capitalize on the 4th Industrial Revolution. Zacks’ urgent special report reveals 6 AI picks investors need to know about today.See 6 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 KeyCorp (KEY): Free Stock Analysis Report Bank of America Corporation (BAC): Free Stock Analysis Report To read this article on Zacks.com click here.