If you're going to mine the data set for patterns, you need to set aside a substantial amount of data to act as a cross validation sample. A priori we should know that the NFL draft data set is not rich enough to support this kind of analysis.
The other possibility is to create a hypothesis before looking at the data, and then you can test your hypothesis (model) against the data. If you peek at the data beforehand, or let what you know about the data bias your hypothesis, then it doesn't really work. This kind of analysis works when you're using it to inform your own decisions under uncertainty, when you have skin in the game. Otherwise there is a principle agent problem - in academic psychology this is called the replication crisis.