What Would a Pessimistic View of Next-10-Year Returns do to Simulated Fail Rates?

In the process of running some tests on my rebuilt simulator, I ran a set of paired tests, each one with 10x1000runs[1]:

  1. Once with a slightly modified table of historical returns,

  2. A second time with same table as a source but returns are
      suppressed in the first 10 years of each sim by a couple pct.
   

The first test had an average fail rate of 9.3% [2].
The second test had an average fail of 15.8%.

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[1] Short runs but I didn't want to wait for 10k runs. Assumed age 65, $1M endowment, 40k constant inflated spend, 60/40 portfolio, uncertain longevity using 2013 SS life table, factor for fees and taxes, etc.

[2] Seems high but note that there are taxes, fees, and fully dispersed longevity uncertainty in there. I wish I could figure out how to feather in some autocorrelation but I couldn't.