Why do salespeople fail? It’s a question that managers as well as their salespeople have asked for decades. And one contributing factor that keeps this question alive and in the forefront of our minds is that there has not been one universally accepted answer. Whether the salesperson's failure is being blamed on the salesperson, on the manager, or on a collaborative effort, the reasons often remain subjective, even elusive, and as such, history is bound to repeat itself. The timeless struggle for a solution continues to plague our thinking, while the collateral damage due to this fallout dominates the manager's time. Whether your team consists of 1,000 salespeople or just one, the simple fact stands: Avalanches roll downhill. It starts from the top. The following are six principles managers need to incorporate in order to build a world-class sales team.