This episode is about letters by Warren E. Buffett to his partners at Buffett Partnership, Ltd. (BPL) detail the firm's financial performance and operational philosophy during 1965. The letters demonstrate BPL’s significant outperformance against the Dow Jones Industrial Average and major investment companies, with the Partnership Results showing a cumulative compounded annual rate of 29.8% compared to the Dow's 11.4% through 1965. Buffett discusses the strategic acquisition of a controlling interest in Berkshire Hathaway Inc. and explains the firm's unconventional but successful approach to low diversification, stating a willingness to invest up to 40% of capital in a single security. He also addresses administrative matters, such as the policies for advance payments and withdrawals and the decision to limit the admission of new partners due to concerns that increased size could harm future results. Finally, the letters emphasize the importance of using the Dow as a long-term yardstick for measuring investment management effectiveness.