When you make decisions, you do so by sorting your values in a hierarchy. Sometimes that is why we find it hard to make a decision. If two important values are equally important we find it difficult to choose one over the other.
The value you put at the top of the hierarchy at any given time is your guiding factor in that moment. You can switch the top value depending on the subject at hand.
If winning is your core value, then anything else can be subordinated to that value. That is where cheating can enter the picture. However, it might not, if the persons value for fair play is higher than their desire to win.
So you can read someone’s value chart by the decisions they make. You can only read their value chart based on their current awareness though. If they haven’t become aware of the other values that could supersede or challenge their top one, then we can only see what they are doing with their current knowledge, self-awareness and personal bias.
Try to not project your story of them onto their value chart. You could say that a person is doing something for x or y reason. You really have no idea. But you can see what seems to be their highest value and get some insight into their intent. Have fun with this observational activity.