If Duncan Mackenzie realized he was in a simulation and he was dependent on some weird 4th Dimension Entity to get better at hockey, he would immediately begin looking for ways to hack the system and cheat the simulation. He would look for the code in the Matrix so to speak. He would realize that, if this is a simulation, then everything that happens on the ice is based on some algorithm that exists in the background. if that is the case, it can be figured out and everything about his play could be optimized. Maybe he sees the patterns on the ice. He find himself always in the right place at the right time for an interception or body check. He would learn exactly where and when to shoot to get goals. He would use every bit of analytical brainpower to come to terms with the truth and use that to his advantage.