An experienced man (or woman) is a person who can predict the behaviour of a system which is otherwise unpredictable, simply because of the amount of experience that he has with the system.
The person might not actually make predictions (as these can themselves alter behaviour), but will act upon certain internal assumptions that he makes about how the system will behave in the future.
I do not mean to say, however, that this enables the man to make better decisions. He is just better informed. Decision making is a different ball game...