It seems to me that a sport must have at least one physical element. For example, if holding your breath for time was a thing, it would be a sport? Under the logic, an argument could be made that it was a sport. Is bronco riding a sport? Is bull fighting is a sport? How about rhythmic gymnastics? All physical in some way. For each, one can improve with practice, like poker. But what about poker in a long tournament, where fatigue can be a real factor, mental and/or physical? In consideration of fatigue in poker, might poker actually be a sport?