ERD50
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
The classic 4% is not 100% safe, even historically. So a big market drop may mean you are on one of the failure paths. ...
... you put your portfolio balance into it and FIRECalc tests scenarios that include retiring just at the start of the Great Depression. If the portfolio balance you input was already at a market bottom (unlike right now), that might be a scenario of two big market drops in a row (the current market bottom plus any number of historical market drops). ... So FIRECalc is probably best used during a market peak, not at a market bottom. ...
That covers it very well. I think that is what photoguy and a few others are missing. FIRECalc is already looking at the worst cases in history, you don't need to re-adjust after a market drop, that is already accounted for with the initial WR, which is carried forward through market dips, and succeeds without further adjustment if you target 100% success rate for that initial WR%.
Again, based on history, but that is all FIRECalc can do. If you think the future may be worse than the worst of the past, build in some appropriate cushion. But use FIRECalc as a guide, and then apply any teaks you wish.
-ERD50