The coaching industry has grown to become a multi-billion dollar business, yet there remain few barriers to entry and an absence of national governing bodies. Wide variation in quality of practice undermines the credibility of a field that has been found to be effective (Grover, S., & Furnham, A. (2016). Coaching as a developmental intervention in organisations: A systematic review of its effectiveness and the mechanisms underlying it. PLoS One, 11(7), e0159137. https://doi.org/10.1371/journal.pone.0159137; Theeboom, T., Beersma, B., & van Vianen, A. E. (2014). Does coaching work? A meta-analysis on the effects of coaching on individual level outcomes in an organizational context. The Journal of Positive Psychology, 9(1), 1–18. https://doi.org/10.1080/17439760.2013.837499). Coaching stakeholders should therefore be motivated to understand what 'good coaching' looks like. However, it remains unclear what it means to be an outstanding, or expert, practitioner, or even whether the construct of expertise applies to the field of coaching. Within this paper, I critique literature that discusses coach expertise, and suggest the philosophical constraints embedded within current thinking imply the need for an alternative conceptualisation of expertise; adaptive expertise. Adaptive expertise is compatible with the complexity that characterises coaching, and prioritises coach decision-making (judgment and reasoning) over coaching outcomes. Many coaching texts largely ignore the construct of decision-making, with the exception of intuitive decision-making. Further research that seeks to understand coach judgment and decision-making will help coaches' develop their practice, and may be a key to demystifying the central role of intuition in coaching. [ABSTRACT FROM AUTHOR]