The document discusses three distinct ranks that sales contributors fall into - top performers (20%), low performers (20%), and the "middle" performers (60%). It argues that traditional approaches of more training and incentives are ineffective at moving the middle performers. Instead, it advocates for a holistic approach using training, mentoring, and coaching to develop abilities and critical success factors like passion, drive, and confidence. This blended approach aims to help individuals reach their full potential through purposeful practice rather than assuming limitations based on innate talent. The implications could be a sustainable step change in performance across organizations if sales leaders adopt this new mindset.