The central thrust of Moneyball was an attempt to find qualities in a player that were undervalued by the market at large, and yet could help teams win games. This undervaluing meant that teams with the right information could acquire players with these traits for less cost than they would otherwise and maintain competitiveness despite fewer resources than other teams.
Necessity is the mother of invention, and the Oakland As of the early 2000s needed some way to keep up with the rest of the powerhouses of the American League. Although Michael Lewis’ Moneyball glossed over some of the big keys of those teams’ successes – notably one of the best starting rotations in baseball year in and out – the theory of market inefficiencies has stayed and built a foundation for teams across the game to attempt to edge each other out every offseason.