its hard to say who in the pro scene is the "smartest" player. i think thats because even when pros make smart decisions, they dont always end up winning or coming out on top of situations. so its hard to tell overall who the most consistently smart player is. that being said, there are some names that come to mind, and usually the smartest players are the ones who win the most clutches(with the contributing factor of their aim, and the mistakes that the enemy players make whether it be their positioning, timing, or aim as well). i would like to say that most decisions made are not as "on the spot" as you think. while in some situations you wonder how in the hell this player knew or expected an enemy in a certain spot and knew the exact timing to peek him, while also predicting where the other remaining enemies are and having the correct timing to aim in their direction as well, most of it comes down to practice. and when i say practice - i mean that they have played enough against a certain team or certain players to know that if somebody flashes this position or throws this smoke on top of the fact that theres a limited amount of information coming from other specific areas of the map, they already have an idea of where to expect a number of enemies to be peeking.. and so if this amount of enemies are pushing a certain area at this time then the remaining enemies should be at this position at this time. the same concept goes for afterplant situations. "if theres 4 alive and the bomb was planted a second ago, and my teammate is in this position already i can assume that theres at least these many players on site holding angles that probably favor their trade, while theres this player and this player probably in this position or he could be flanking since my teammate rotated here from there"