We begin by outlining the progression of behavioural instruments (BI) in sport. Followed by a description of the process for establishing inter- and intra-rater reliability of the Behavioural Rating Scale for Cricket Bowlers (BRSCB), a new BI devised of 10 in-performance behaviours allied with cricket bowlers. Method. A selected sample were trained in the use of the BRSCB before participating in two data collections. Percentage agreement and intra-class coefficients where used to assess the BRSCB’s reliability. Results. The overall percentage agreement scored adequate reliability (78%) whilst the overall coefficient achieved excellent reliability (0.96). Discussion. Achieving adequate and excellent reliability gives the lead author confidence that the BRSCB will be successful in the applied setting