Do larger than required withdrawals in one year reduce required withdrawals in subsequent years by a factor greater than the reductuin of the year-end balance?

The minimum required distribution(RMD) for people age 70-1/2 and older is calculated by multiplying the value of the account as of Dec 31 of the previous year by a percentage that the IRS mandates based on your age. So if you make a large withdrawal in year 1, then presumably the balance at the end of year 1 would be less, and consequently the RMD for year 2 would be less than it otherwise would have been. But factors such as market performance can affect the value of the account, and hence the size of the RMD. Also be aware that each year the factor for the RMD goes up as you get older. Hope this helps.