Many theories of complex cognitive‐motor skill learning are built on the notion that basic cognitive processes group actions into easy‐to‐perform sequences. The present work examines predictions derived from laboratory‐based studies of motor chunking and motor preparation using data collected from the real‐time strategy video game StarCraft 2. We examined 996,163 action sequences in the telemetry data of 3,317 players across seven levels of skill. As predicted, the latency to the first action (thought to be the beginning of a chunked sequence) is delayed relative to the other actions in the group. Other predictions, inspired by the memory drum theory of Henry and Rogers, received only weak support.