Subject: Re: Thoughts on Berkshire withdrawal strategy
So I used the tool Adrian mentioned at https://testfol.io to backtest a $60,000 fixed annual withdrawal (not inflation adjusted) from a 100% Berkshire portfolio.

This is interesting but not very useful. The purchasing power of a fixed dollar amount over even 10 years is much lower. Over 30 years, it's horrible. Assuming you need the funds to pay for living expenses, you have to make allowance for the effect of inflation.