He’s shooting sports, and the highest priority is freezing the motion, so either shutter priority or better yet, manual with auto ISO is the mode of choice. You pick the minimum shutter speed to freeze the motion and an aperture that provides enough DOF without too high an ISO under worst case, and then, let the auto ISO take care of varying light conditions. Simple, especially with the OP’s FF 6D which can easily handle ISO 12,800 with acceptable noise.
Let me also add, and I’m using NIKON vernacular but it should translate well, for basketball I shoot in matrix metering mode.
For hockey, depending on venue I will sometimes spot meter.