>>213018874'Moneyball" meant identifying assets that were undervalued by baseball teams in general. That way a team like Oakland could go after those kinds of players and have a surprisingly good team without blowing their budget.
At the time, skills likr getting on base were undervalued compared to things like batting average or hitting home runs. Getting on base has always been important in baseball, but for a long time most people didn't really understand exactly how important it was. The reason they say that defense doesn't matter in the movie is not because it actually doesn't matter, but because at the time there still were not sufficient and reliable statistical ways of analyzing defense. So it didn't really help them to use that as a basis for valuing players and getting a comparative advantage. Analyzing defense back then involved a lot of appeal of authority and hearsay and other stuff like that. It just wasn't reliable yet. Nowadays baseball has much better defensive statistics.
These days, the kinds of assets that you would go after which are undervalued would look different from how they looked during the time the movie is about but is still the same basic principle. The Tampa Bay Rays have been very smart for a very long time with small budgets. The Milwaukee Brewers the last few years are another example.