The factors, which must be taken into account are called "hidden variables-, and could never be established with sufficient accuracy. .
This theory, first thought by Einstein, is an alternative way of looking upon probability. In the view of this scientist, nothing happens by chance due to these "hidden variables- and that they are solely responsible for the occurrence of randomness, as they make each electron different from one another. This belief that the quantum world must have an un-measurable reality is known as the Neorealist View. So in reality, those who follow the Neorealist view don't actually believe in chance. The view in which I am choosing to follow was recognised by Bohr and Heisenberg, in that the quantum world doesn't really exist and all that can be discussed are the probable outcomes of a system. For example, an observer doesn't actually know if a coin will land heads or tails until it lands! This opinion fits entirely with probability theory and the role of chance in the physical universe. .
Before going into greater depth about the probability related to my chosen system, we must first understand about two state systems. A system, in quantum physics can be explained by a superposition of numerous possible final states. Of course the tossing of a coin is the one of the simplest systems, which can be used. We all know that if we have a fair coin, it is equally likely that heads or tails may result from each throw, so each would have a 50% chance. If a measurement is made there is a probability, (P), of one outcome and probability of, (1-P) for the other. So, the tossing a coin can basically be described as a two state system. On the other hand, it is also known as an unpolarized system. .
This is because if a system is always in one state it is known as fully polarised, but due to the fact that either state, heads or tails, is likely, this system is known as unpolarized.