Spatial Reasoning and Memory, a Chess Player's Friends
When looking at two of the most important things you need to train (besides strategy ofcourse) in order to be a better chess player, the answer relies deep in the mind. Spatial reasoning for better decision making, and memory to better memorize patterns, strategies and past mistakes are two crucial tools to improve your gameplay overall.
All the geometric patterns you see on the chess board can be thought of as spatial reasoning puzzles needing to be solved. Think of how you react to a player as your best answer to the next potential possible outcome.