Book excerpt: Today's corporate deal makers face a conundrum: Though 70% of major acquisitions fail, it's nearly impossible to build a world-class company without doing deals. In Mastering the Merger, David Harding and Sam Rovit argue that a laserlike focus on just four key imperatives--before executives finalize the deal--can dramatically improve the odds of M&A success. Based on more than 30 years of in-the-trenches work on thousands of deals across a range of industries--and supplemented by extensive Bain & Co. research--Harding and Rovit reveal that the best M&A performers channel their efforts into (1) targeting deals that advance the core business; (2) determining which deals to close and when to walk away; (3) identifying where to integrate--and where not to; and (4) developing contingency plans for when deals inevitably stray. Top deal makers also favor a succession of smaller deals over complex "megamergers"--and essentially institutionalize a success formula over time. Helping executives zero in on what matters most in the complex world of M&A, Mastering the Merger offers a blueprint for the decisions and strategies that will beat the odds.