The purpose of this study was to investigate expert coaches’ conceptions (internal models) of the fast-bowling technique, how they coached it and how they acquired the knowledge for both. Twenty expert cricket coaches from around the world, took part in semi-structured interviews, with all interviews being transcribed verbatim. Thematic analysis (Braun & Clarke 2006) was carried out and thematic networks (Attride-Stirling, 2001) were produced for the coaches’ models of a ‘good’ fast-bowling technique, a ‘poor’ fast-bowling technique; coaches’ approaches to coaching; and coaches’ sources of knowledge. The coaches’ model of a ‘good’ fast-bowling technique matched the empirical literature findings, as did the model of a ‘poor’ technique, with both models using the six-phase technique (Bartlett et al 1996). It is believed that the model of a ‘poor’ technique is the first of its kind to be produced. Fetisova et al (2020) suggested that coaches (expert and non-expert) tend to be able to identify the individual components of a technique, but the ability to distinguish the ‘big picture’ of the technique, how individual elements fit together and the biomechanical principles that cause this, are the factors that differentiate the expert coaches from the non-expert coaches. The coaches’ explicit discussion of biomechanical principles was varied across the cohort. The coaches’ approach to coaching was broken down into six sub-themes: ‘Coaching philosophy & beliefs’, ‘Physical and mental preparation and development’, ‘Coaching environments and interventions’, ‘Coach-player relationships and communications’, and ‘Other factors’. Coaches believed strongly in individualising coaching analysis and interventions and stated a preference for holistic development. However, there was little discussion of variation to pedagogical approaches, with coaches having a strong preference for using drill-based coaching interventions. The coaches’ sources of knowledge were also pulled into six sub-themes: ‘Experience, Coach education/CPD’, ‘Other formal professional knowledge and education’, ‘Conversations with other experts’, ‘Self-directed study’, and ‘Personal theory and experimentation’. Coaches built their knowledge and expertise in a non-linear fashion. Coaches preferred referring to former and current high-level performers as models of technique and worked closely with