Most Americans finance their retirement with a certain amount of faith, investing will help their savings keep pace with inflation, institutions will continue to work, it will all work out in the end.

It is difficult to maintain optimism when things seem to be at stake and nothing is certain. You wouldn't be wrong if you said the American approach to retirement gambling was called the American approach.

The future has never been certain. It was not known in 1973, when one of the highest-inflation periods, and in 2000, when the dot-com bubble burst. When the markets are down about 11 percent year to date and inflation is high, it is hard to know what is going on. When the stock market plummets, bonds usually provide some cushion, but they haven't provided much of a buffer.

Christine Benz said that falling stock prices, falling bond prices and high inflation have been unnerving for retirees.

Retirees don't have the benefit of waiting it out. It's important that the timing is right. Market declines that occur during the first five years of retirement can do significant and permanent damage, making it more likely a portfolio will be deplete. It is less risky to experience such a decline further into retirement because the money doesn't have to last as long.

Even in periods of high inflation, people who retired into different downturns did well. The bad news is that their portfolios did not perform well. Past performance can't guarantee future results.

According to the 4 percent rule of thumb, retirees who withdraw 4 percent of their retirement portfolio balance in the first year are more likely to create a paycheck that lasts 30 years.

The framework was used by T. Rowe Price to analyze how a $500,000 portfolio of 60 percent stocks and 40 percent bonds would fare over the course of 30 years. The last two periods are still going strong. Each year, they would increase the amount withdrawn by the previous year's inflation rate.

The oil embargo and high inflation rates echo the present. By September 1974, the analysis found, retirees' portfolios would have shrunk to $328,000, or nearly 35 percent, and inflation would have risen by more than 12 percent. A one-two punch.

The retirees had no idea when they retired that their portfolio balance would reach $500,000 again. At the end of 30 years, the portfolio had doubled in value to over $1 million.

According to Judith Ward, a senior financial planner and thought leadership director at T. Rowe Price, starting out with a 4% withdrawal rate is all that's on the table.

The portfolios of people who retired in 2000 or 2008 may have done worse than those who retired in 1973.

The retirement portfolio has a balance.

It begins with $500,000.

The years were 1973, 2000 and 2008.

The S&P 500 is the stock market's main index. The retirement portfolio balance is based on an asset allocation of 60 percent stocks and 40 percent bonds and a withdrawal amount of 4 percent in the initial year.

By Karl Russell.

She admitted that retirees don't spend in straight lines, and that they spend more later in retirement. She said the study shows the importance of starting with a conservative spending plan when a portfolio is down. She said that the lever of how much you spend is a strong one.

In the periods after 2000 and 2008 when the stock market lost half its value, the portfolios were projected to be sustainable even though retirees still have eight and 14 years to go before they reach 30 years of retirement. One scenario in which inflation persisted at 9 percent for the rest of the 30-year retirement period was held for by Ms. Ward.

Ms. Ward said the scenarios assumed the investor didn't adjust their behavior because of the steep market losses. Retirees would probably want to modify their plans in some way. She said that it added an even stronger margin of safety.

Retirees shouldn't take too much comfort in the past results because the future is always uncertain, according to other experts.

The head of retirement research at the asset management firm said that using the past gave false confidence. The US and Australia have two of the best capital markets in the world. It's useful, but you have to look ahead.

Financial experts suggest taking a flexible approach to withdrawals, focusing on what you can control as the situation changes.

Some strategies might help.

A new way of thinking. Think about your withdrawals in terms of needs, wants and wishes. How much of your basic needs are covered by Social Security or pensions, and how much more do you need to withdraw to cover the rest? The withdrawal rate may be 3 to 4 percent, but your wants may be anywhere from 4 to 6 percent. It's the most important thing to have your needs covered.

There is a bucket. The idea is to keep at least a year's worth of basic expenses in cash or something equivalent so that retirees experiencing a downturn can spend out of this bucket instead of having to touch their portfolio.

It can ease anxiety for retirees who find comfort in being part of a group. Critics have said keeping a meaningful amount of a portfolio in cash may pose a drag, hurting returns over the long run, but for many retirees it may give them a plan they can stick with.

There are guardrails The strategy was created by the financial planner Jonathan Guyton and the computer scientist William Klinger.

Retirees are usually safe if they start out with a withdrawal rate of 5 percent for the first year, then adjust it up each year for inflation, as long as they cut back when they receive a warning signal.

The warning light goes off when the withdrawal rate goes above the initial rate. Retirees would need to reduce their withdrawal dollar amount by 10 percent if the portfolio plummets and the amount withdrawn now equates to 6 percent or more.

A retiree who retires in the first year gets 5 percent of their $500,000 portfolio. The next year's withdrawal would increase if inflation was 9 percent. If the portfolio plummeted to $415,000, the amount withdrawn would need to decline to $24,525, which is 10 percent less than $27,250.

The retiree can increase the dollar amount withdrawn by 10 percent if the portfolio grows and the withdrawal rate shrinks.

An 85-year-old couple who want to be safe until age 100 can stop using it if they don't want to leave a lot of money to their heirs.

Make sure to check up. The rule of thumb helps retirees figure out if they are withdrawing too much.

You will most likely need your money to last until 95 if you retire at 70. Divide the number of years you need the money to last by 25 and you'll get a withdrawal rate of 4%. That's $20,000 with a half a million portfolio.

If you pull out $30,000 that year, you might want to rethink. He said it was an ongoing gut check. Is this going to last? That is a very easy way to get an answer.

If you don't adjust. It is possible that you will have to make more drastic changes in the future.

He said that you are just trading money with yourself.