Investors interested in stocks from the Financial - Investment Management sector have probably already heard of Affiliated Managers Group (AMG) and T. Rowe Price (TROW). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Currently, Affiliated Managers Group has a Zacks Rank of #2 (Buy), while T. Rowe Price has a Zacks Rank of #3 (Hold). Investors should feel comfortable knowing that AMG likely has seen a stronger improvement to its earnings outlook than TROW has recently. But this is just one piece of the puzzle for value investors.Value investors also tend to look at a number of traditional, tried-and-true figures to help them find stocks 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.AMG currently has a forward P/E ratio of 10.56, while TROW has a forward P/E of 17.12. We also note that AMG has a PEG ratio of 0.70. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. TROW currently has a PEG ratio of 1.90.Another notable valuation metric for AMG is its P/B ratio of 2.45. 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, TROW has a P/B of 5.97.Based on these metrics and many more, AMG holds a Value grade of A, while TROW has a Value grade of C.AMG has seen stronger estimate revision activity and sports more attractive valuation metrics than TROW, so it seems like value investors will conclude that AMG is the superior option right now. Zacks' Top Picks to Cash in on Artificial Intelligence In 2021, this world-changing technology is projected to generate $327.5 billion in revenue. Now Shark Tank star and billionaire investor Mark Cuban says AI will create "the world's first trillionaires." Zacks' urgent special report reveals 3 AI picks investors need to know about today.See 3 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 Affiliated Managers Group, Inc. (AMG): Free Stock Analysis Report T. Rowe Price Group, Inc. (TROW): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research