What feature or filter can help you investigate why two videos of the same length have different audience retention metrics?

The Comparison feature in YouTube Analytics allows you to directly compare the performance of two or more videos, or even different time periods for the same video. This is crucial for investigating discrepancies like varying audience retention for videos of similar length. By comparing them side-by-side, you can identify specific moments where one video lost viewers while the other retained them, helping to pinpoint content or pacing differences. "Filter" is too broad; while you can filter by video, it doesn't offer a direct side-by-side comparison of metrics. "Groups" is for organizing videos, not for comparative analysis of individual video metrics. "Date range" helps analyze performance over time but doesn't facilitate a direct comparison between two distinct videos.