I'm 62 and closing in on end of salary. Since I've already made my "minimum" and then some, I've committed to this "just-a-bit-flexible" plan:
1) When portfolio is at ATH (now) 50/50 - cuz nobody knows nothing, that level of risk lets me sleep and historically has returned more than I "need".
Details: equity is 80/20 us/int, fixed is total-bond and "cash"
Cash is stuff like CD ladder, TIPS... and is always kept at 10 yrs of "minimum" income
2) When equites fall, rebalance to 50/50 from bonds - cuz if equities were worth buying at higher prices, they still must be!
I only do this if equites fall by 1/8. And I only do it down to 50 %. So, a max of 4 times.
#2 is never allowed to touch the cash.
(The idea is that I can always ignore equites and bonds for 10 years)
3) Once #2 triggers, if equites rise, my AA will skew towards equites, and I let it ride (this is the flex part)
Let it ride until the entire portfolio is at ATH, then reset to a new #1.
(The idea is that I will be back to ATH before the market is, actually lowering my risk!)
During withdrawal phase (coming soon!) I will also adjust for withdrawals.
I admit this is almost identical to 50/50 at ATH, rising to 60/40 if equity declines. And my version is more complicated. And it's not a mathematical guarantee.
But it satisfies my itch to outsmart the market while keeping me inside the guardrails.