Corrected Results page for the 10MMA variant attached.

With the corrected data, the results change quantitatively, but not qualitatively. Using 100% bonds as the ballast for stocks still seems best here overall. Using a 4.0% IWR, FVs all still exceed 99% of initial over 30 years. The November 1965 cohort shows a 3.96% average consumption, while the March 1937 cohort is “only” 3.88%.

If you use a 4.25% IWR, the 1965 cohort exceeds 4% average consumption, while the 1937 one gets up to 3.94%, and FVs go down but remain high enough to safely support a 60 year retirement. So using 10MMA you don’t quite “save” the 4% rule for early retirees, but it seems you can exceed 3.9%. And perhaps someone can do the math and achieve 4.0% or more if your 60 year FV target is below 50%.

And 4% appears quite doable for those of us not concerned about sustained deflation.

v2.0 - now in Time Series form in a single sheet

@earlyretirementnowcom Ok, I did as you suggested and created a return time series (two actually - one for my “home-brewed” asset allocation formula, and one for Meb Faber’s simple 10 MMA) that I fed into the two Custom Time Series columns in your StockBondReturns tab. Attached.

I did it by creating a clone of the StockBonds Return tab to do all the calculations. And once I realized that I was doing a momentum-based timing strategy rather than a glidepath replacement, I made the home-brewed formula more aggressive, in particular cutting stocks to zero when the sell signal occurs. 

Note that within that tab I created two (on-tab use only) custom series to choose between Bonds and Gold as the ballast. The simple one is just the bond series through August 1971, and the gold series thereafter.  The more complex one tries to choose between the two based on inflation, disinflation, bond yields. While I think this second one might be pretty good being used with a static stocks allocation, when used with the two stock timing strategies, the simple Bonds-Gold combo is superior, and so that’s the only one of the two I actually use together with the stock formulas. [If for some reason you find even such a simple hybrid "offensive", you can simply use gold as the ballast throughout, with slightly worse results for the 1920s through 1950s.]

The results are pretty spectacular in terms of SWRs possible. The home-brew delivers higher SWRs, and much higher post-1950 SWRs [though the simple 10 MMA is pretty spectacular for the period since 1990). To the extent one doesn’t understand my home-brew momentum strategy, or fears that it is an overfit, the simple 10 MMA still yields substantially better results than the best glidepaths.

As before, at 80% FVs for 30 years, you see post-1950 SWRs well north of 4%, and 1930s SWRs north of 3.7%, with the home-brewed version delivering substantially higher numbers than the 10 MMA.

FWIW, with a 0% FV, you see a 4.26% overall SWR, and a 4.91% post-1950 SWR using the 10 MMA, while with the home brewed version you see  a 4.56% overall SWR, and a 5.85% post-1950 SWR!

Note that while I do still believe “in real life” the use of my proposed guardrails both safely allows higher average consumption under almost every scenario, and reflects prudent policy to handle “worse than anything ever seen” and more likely reflects and is consistent with what most people would (and arguably even should) do when confronted with a steep (35%+) drop in their  portfolio, and so is worthy of additional study and discussion, I now do take your point that it first makes sense to look at the momentum based strategies without said guardrails. For one, that is the best way to guide what an initial WR should be, and to set approximate expectations for worst case average consumption using such a guardrail approach.

Feel free to ask any additional questions - and to poke holes in the home-brewed timing methodology (or anything else in this hack).

Perhaps later I’ll post some more numbers. And maybe continue to tweak my home-brewed scheme as well.  After decades of ignoring or disdaining it, and still not believing it the way to go in the accumulation phase, all of a sudden I’m in love with the concept of market timing in the context of retirement math.

Looks like the file didn't upload properly the first time - trying again.