Is drilling or rolling more important for BJJ improvement?

Drilling allows you to perform hundreds of repetitions of a technique with proper form, building the neural pathways needed for automatic execution. Without drilling, you will struggle to apply techniques under the stress of live rolling. Rolling reveals which techniques you can actually execute against resistance and exposes gaps in your game. Without rolling, you have an unrealistic picture of your abilities. The ideal training session includes both. Drill the techniques taught in class, then deliberately try to apply them during rolling. Positional sparring bridges the gap between drilling and rolling by letting you practice specific situations with resistance. Some practitioners lean too heavily toward one side. Those who only drill have beautiful techniques but cannot apply them live. Those who only roll develop a limited game based on what works against their training partners without expanding their repertoire.