Under the ownership of Walter A. Haas, Jr., the Athletics appeared in three consecutive World Series from 1988 through 1990, and had the highest payroll in baseball in 1991. Haas died in 1995, and new owners Stephen Schott and Ken Hofmann ordered Alderson to slash payroll. To field a competitive roster on a limited budget, Alderson began focusing on sabermetric principles to obtain undervalued players. He valued on-base percentage among hitters. Alderson taught Beane to find value that other teams did not see using sabermetrics.