It's not really gambling so much as there not being any one answer 100% of the time. Otherwise there wouldn't really be a game. Everything comes down to probability. There is no such thing as a safe option, just what is most likely to be safe in a given situation. You want to identify and commit to those options, but sometimes you might want to go out on a limb and take a bigger risk if you have a feeling it will work. The best players can juggle all of those situations and pick the right one at the right time in the heat of a match, while pressuring the opponent to pick wrong.
So ultimately it comes down to judgement, which is why you see the same players placing high consistently. And of course, developing the skills to make sure you can execute that judgement.