W. Edward Deming, the management and quality guru, said best when he told executives that managing a company by looking at financial data (lag measures) is the equivalent of "driving a care by looking in the rear view mirror."
The following comes from "The 4 Disciplines of Execution" by Chris, McChesney, Sean Covey and Jim Huling. From the coaching stand point I think it means that we can't rely solely on statistics to advance our team. It's about relationship and developing players instead of just numbers. Paying to much attention to stats from former games keeps you living the in the past. Analyze the data, and then get to work on making players better.