Two factors often determine stock prices in the long run: earnings and interest rates. Investors can't control the latter, but they can focus on a company's earnings results every quarter.Life and the stock market are both about expectations, and rising above what is expected is often rewarded, while falling short can come with negative consequences. Investors might want to try to capture stronger returns by finding positive earnings surprises.The ability to identify stocks that are likely to top quarterly earnings expectations can be profitable, but it's no simple task. Here at Zacks, our Earnings ESP filter helps make things easier.The Zacks Earnings ESP, ExplainedThe Zacks Earnings ESP, or Expected Surprise Prediction, aims to find earnings surprises by focusing on the most recent analyst revisions. The basic premise is that if an analyst reevaluates their earnings estimate ahead of an earnings release, it means they likely have new information that could possibly be more accurate.The core of the ESP model is comparing the Most Accurate Estimate to the Zacks Consensus Estimate, where the resulting percentage difference between the two equals the Expected Surprise Prediction. The Zacks Rank is also factored into the ESP metric to better help find companies that appear poised to top their next bottom-line consensus estimate, which will hopefully help lift the stock price.Bringing together a positive earnings ESP alongside a Zacks Rank #3 (Hold) or better has helped stocks report a positive earnings surprise 70% of the time. Furthermore, by using these parameters, investors have seen 28.3% annual returns on average, according to our 10 year backtest.Stocks with a #3 (Hold) ranking, which is most stocks covered at 60%, are expected to perform in-line with the broader market. But stocks that fall into the #2 (Buy) and #1 (Strong Buy) ranking, or the top 15% and top 5% of stocks, respectively, should outperform the market. Strong Buy stocks should outperform more than any other rank.Should You Consider Redwood Trust?The final step today is to look at a stock that meets our ESP qualifications. Redwood Trust (RWT) earns a #2 (Buy) eight days from its next quarterly earnings release on February 9, 2022, and its Most Accurate Estimate comes in at $0.36 a share.RWT has an Earnings ESP figure of 5.88%, which, as explained above, is calculated by taking the percentage difference between the $0.36 Most Accurate Estimate and the Zacks Consensus Estimate of $0.34. Redwood Trust is one of just a large database of stocks with positive ESPs. These stocks can be filtered by ESP, Zacks Rank, % Surprise (Last Qtr.), and Reporting date.Don't forget to head to the Earnings ESP Home Page. There, you'll find lots more earnings-related investing strategies to help build a winning portfolio.Find Stocks to Buy or Sell Before They're ReportedUse the Zacks Earnings ESP Filter to turn up stocks with the highest probability of positively, or negatively, surprising to buy or sell before they're reported for profitable earnings season trading. Check it out here >> 7 Best Stocks for the Next 30 Days Just released: Experts distill 7 elite stocks from the current list of 220 Zacks Rank #1 Strong Buys. They deem these tickers "Most Likely for Early Price Pops." Since 1988, the full list has beaten the market more than 2X over with an average gain of +25.3% per year. So be sure to give these hand-picked 7 your immediate attention. See them now >>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 Redwood Trust, Inc. (RWT): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research