I do not think you understand this correctly. To do statistical odds against chance there must be an objective way of judging.
Let me give the simplest example.
In a Ganzfeld experiment a sender tries to psychically send a random image to a receiver person. The receiver is then asked to select which of four random images the sender was seeing. If materialism is correct, the receiver should be correct 25% of the time. But if the score is higher than 25% over a large sample size then the odds of a materialist explanation can be precisely calculated. Utts' involvement is in being a recognized expert in statistical analysis.
My point is that parapsychologist understand the subjective stuff you are talking about so they devise ingenious ways to remove subjective judging.
Here is more detailed description:
Experimental procedure
In a typical ganzfeld experiment, a 'receiver' is left in a room relaxing in a comfortable chair with halved ping-pong balls over the eyes, having a red light shone on them. The receiver also wears a set of headphones through which white or pink noise (static) is played. The receiver is in this state of mild sensory deprivation for half an hour. During this time a 'sender' observes a randomly chosen target and tries to mentally send this information to the receiver. The receiver speaks out loud during the thirty minutes, describing what he or she can see. This is recorded by the experimenter (who is blind to the target) either by recording onto tape or by taking notes, and is used to help the receiver during the judging procedure.
In the judging procedure, the receiver is taken out of the ganzfeld state and given a set of possible targets, from which they must decide which one most resembled the images they witnessed. Most commonly there are three decoys along with a copy of the target itself, giving an expected overall hit rate of 25% over several dozens of trials.
However before we get off on this tangent, this is only one reason for my rejection of materialism. We are splitting just one strand of hay with this discussion in a haystack of reasons I have given for rejection of materialism.