Play to Win: How Strategy Really Works is an 8-chapter books published in 2013 by Harvard Business Review Press and written by former Procter & Gamble CEO A.G. Lafley and Rotman School of Management Dean Roger L. Martin. The authors present a framework for creating strategy based on a decade of work at P&G. The framework is a strategic choice cascade, made up of 5 decision points that apply to companies of all sizes and in all markets. The model guides leaders in making choices around a winning aspiration, where to play, how to win, core capabilities, and management systems and is enriched by using the context of P&G's experience. The authors provide perspectives on how to put the framework into practice, offering practical tips and personal insights. Chapter 5, Play to Your Strengths (24 pages), looks at the fourth step in the model, core capabilities. These are the activities that convey the competitive advantage necessary to win in the marketplace. Identifying, aligning, and supporting the correct core capabilities is necessary to implement the strategic choices determined in the first two steps: where-to-play and how-to-win. The authors discuss this step in the context of P&G's acquisition of Gillette and the overall choice cascade for this strategy. They present an adaptation of Michael Porter's "activity system" as a guide for identifying an organization's most important activities and ensuring that they are feasible, distinctive, and defensible. The authors also apply this concept in organizations with more than one product line and multi-level strategies.