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Troubleshooting

Why the projection and success odds differ

A single projection and a distribution of trials answer different questions.

Updated

Where this happens in a plan year

1of 8 stages

  1. Events
  2. Growth (covered)
  3. Required
  4. Income
  5. Spending
  6. Cash flow
  7. Taxes
  8. Year end
On this page
  1. Bad years early are what break a funded projection
  2. The median trial isn’t the projection
  3. Settings that change the rate
  4. Symptoms and checks

The overview projection applies your assumed rates every year, so it shows one smooth path. The Success odds tab runs the same plan through many market histories and counts how many trials run out. A plan can be funded in the projection and still fail in a large share of trials. A projection that runs out can also succeed in many trials.

Neither result is wrong. They answer different questions: what happens if markets match your assumptions every year, and how often the plan survives when they don’t.

The most common cause. In the projection every year earns the same return. In a trial, a run of losses while you’re withdrawing forces sales at low prices, and the money sold never recovers. A trial with the same long-run average return as your assumption can still run out if its bad years come first.

$40,000 of spending

The projection is funded through the plan’s end with $771,797 left. 69.3% of trials succeed.

$45,000 of spending

The projection runs out in its final year. 58.3% of trials still succeed.

Both use the same example plan: $1,000,000 in a brokerage account at 60, 40% bonds, plan default rates, 1,000 trials. A thin margin at the end of the projection usually means a success rate near half, in either direction.

$40,000 of spending: the projection against the spread of trials
  • 90th percentile
  • Median
  • 10th percentile
  • Steady-return projection
−$2M$0$2M$4M$6M$8M2030203520402045205020552060

The projection stays inside the middle of the spread, but the 10th percentile runs out at 84.

Show data
$40,000 of spending: the projection against the spread of trials
Year10th percentileMedian90th percentileSteady-return projection
2026$903,695$1,050,855$1,191,426$1,016,947
2027$844,993$1,076,355$1,279,472$1,033,646
2028$849,125$1,112,791$1,382,473$1,050,045
2029$826,110$1,108,057$1,418,480$1,066,089
2030$815,884$1,159,919$1,533,379$1,081,717
2031$765,045$1,154,955$1,650,942$1,096,865
2032$755,285$1,176,233$1,744,086$1,111,465
2033$736,868$1,209,473$1,861,436$1,125,440
2034$726,794$1,262,392$1,960,457$1,138,712
2035$700,499$1,236,553$2,052,218$1,151,193
2036$665,616$1,253,231$2,177,830$1,162,791
2037$649,097$1,287,465$2,339,571$1,173,406
2038$608,497$1,305,235$2,500,296$1,182,933
2039$582,184$1,337,811$2,608,519$1,191,256
2040$546,603$1,356,916$2,718,399$1,198,253
2041$509,830$1,368,980$2,827,490$1,203,793
2042$470,624$1,412,642$2,927,024$1,207,736
2043$421,581$1,421,444$3,097,985$1,209,931
2044$372,605$1,435,419$3,245,577$1,210,218
2045$324,680$1,427,118$3,385,770$1,208,425
2046$264,203$1,462,917$3,572,345$1,204,368
2047$207,954$1,462,463$3,698,620$1,197,852
2048$146,521$1,465,654$3,963,867$1,188,667
2049$53,558$1,464,605$4,109,049$1,176,588
2050−$56,554$1,496,442$4,384,975$1,161,379
2051−$131,409$1,444,973$4,627,238$1,142,784
2052−$215,355$1,452,018$4,801,611$1,120,532
2053−$314,718$1,472,230$5,053,376$1,094,334
2054−$419,476$1,469,517$5,246,729$1,063,880
2055−$507,483$1,464,069$5,670,521$1,028,842
2056−$618,184$1,404,668$5,733,979$988,870
2057−$747,828$1,417,931$6,136,271$943,590
2058−$884,473$1,403,716$6,435,965$892,604
2059−$1,032,042$1,438,848$6,915,241$835,490
2060−$1,169,270$1,384,414$7,286,081$771,797

The median line is the middle value of all trials in each year, not a trial of its own. It can end well above or below the projection. In the example it ends at $1,368,356 against the projection’s $771,797, yet 30.7% of trials run out. Judge risk by the success rate and the lower percentiles, not by where the median ends. See Success odds.

  • Calibration off. Trials then use unadjusted history, which returned more than the 7% default. The example rises from 69.3% to 90.7%.
  • Failure definition. Both tests fail a trial in any year spending goes unpaid. The default also fails it when cash and investments reach zero. The net-worth test instead fails it when debts exceed everything owned, which can happen while spending is still paid.
  • Targets. A final net worth target or counting flexible-spending cuts affects only the target success rate, not the funding success rate.
  • Trials and seed. The same seed repeats the same result. More trials move it by about a point: the example is 69.3% at 1,000 trials and 68.5% at 5,000.

Settings are in Success oddsRun settings and success criteria.

You seeCheckThen
The projection is funded, but the success rate is low.
How much is left at the end of the projection, and when the lower percentiles cross zero.
Expected when the margin is thin or withdrawals start early. See Success odds.
The projection runs out, but many trials succeed.
The year the projection runs out. Late shortfalls leave roughly half the trials funded.
Look at the failure analysis’s average age at failure.
The success rate is much higher than expected.
Whether calibration is off.
Turn calibration on to center trials on your assumptions.
One account barely varies across trials.
Whether the account has its own fixed stock growth or dividend yield.
Clear those fields to let it follow sampled returns. See Market, inflation and wage assumptions.
The median ends far from the projection.
The median is ranked year by year across trials.
Compare success rates and the 10th percentile instead.
Rerunning gives exactly the same result.
The random seed. It defaults to 42.
Clear the seed for an independent run.

To see how one bad historical period plays out year by year, replay it in the Historical stress test.

Next in Assumptions and analysisCopy a plan and compare changes