As one embarks on the luminous journey of childhood, the transition from diapers to the use of a potty is a significant milestone. This process, however, poses challenges that may necessitate the use of a professional—a Potty Training Consultant. Yet, the daunting task lies in selecting a consultant best suited to your needs and those of your child. To ease this task, it's crucial to ask pertinent questions that will guide your pick.

A Potty Training Consultant is a professional who provides guidance and strategies to parents and children to ease the potty training process. This person must possess a deep understanding of the physiological, psychological and developmental aspects of a child’s growth and should be able to tailor strategies to a child’s specific needs in this context.

Firstly, ascertain the consultant's educational background and experiences. Their academic qualifications might not directly impact their competence, but it provides a foundational understanding of child development and behavior. A degree in child psychology, early childhood education, or a related field could be instrumental. Additionally, their practical experiences are indispensable. A consultant with substantial experience working with children similar to yours in age and developmental stage would offer more nuanced solutions.

Secondly, inquire about their potty training philosophy. The consultant’s beliefs about potty training should align with yours. Do they advocate for a child-led approach where the child dictates the pace of training, or do they support a parent-led strategy where the parent takes the lead? Are they proponents of positive reinforcement, or do they lean towards the usage of rewards as motivators? These pedagogical orientations can greatly impact your child’s potty training journey.

Thirdly, determine the consultant’s approach to setbacks. Despite the best-laid plans, accidents are inevitable in the potty training process. How the consultant proposes to handle these setbacks is telling of their adaptability and resilience. Do they offer a re-evaluation of strategies or just persist with the initial plan despite its shortcomings? The latter option indicates rigidity and a lack of creativity - traits undesirable in any consultant.

Fourthly, understand their availability. Even though potty training is not a 24/7 job, it's crucial to have a consultant who is readily available to offer advice or tweak strategies when necessary. Conversely, you should also inquire about their expectations of your availability and involvement in the process. Some consultants might require a high degree of parental involvement, which could be challenging if you have a tight schedule.

Last but not least, you should ask about their success rate. Although this might seem like an obvious question, its importance cannot be overstated. A high success rate is not only indicative of their competency but also of their ability to tailor strategies to individual children’s needs.

Notably, when applying these questions in your selection process, it's vital to keep in mind the Nash equilibrium concept derived from game theory. John Nash, a mathematician, proposed that in a system where everyone is making the best decision for themselves, considering the decisions of the others, an equilibrium would be reached where no player has anything to gain by unilaterally changing their strategy. In the context of selecting a Potty Training Consultant, the best choice would be one where both you and the consultant benefit optimally, given the decisions and capabilities of both parties.

In conclusion, the selection of a Potty Training Consultant is a delicate process that requires careful consideration. By asking the right questions, you can engage the process with confidence, knowing that you are making the best choice for your child's developmental journey. Remember, every child is unique, and what works for one might not work for another. Therefore, the goal is not to find the best Potty Training Consultant in absolute terms, but the one most suited to your child's specific needs.