Purposefully choosing goals that you don’t yet know how to achieve is one of the powers of OKRs; they’re not meant to be limited to project plan-style marches towards a known outcome.
Take the classic YouTube “one billion hours in daily user watch time” by the end of 2016, which was about a 10x multiple over their 2012 stat. There’s no way they knew how to reach that goal, but the objective helped them to align and constantly make small decisions in support of that goal (instead of other conflicting goals, each of which could be argued to be good for Google in a different way).
Did somebody in the room say, "We've crunched the numbers, and our best estimation is that if we orient all our resources toward achieving this goal and put forth our best possible effort, we'll be able reach 5x."
And then did somebody else in the room say, "I agree. So let's be extremely audacious and shoot for 10x"?
Either the first person was miscalculating or the second person was being unreasonable.
If you know how to do 4x, but think 10x is epsilon away from “best possible”, you set a 10x objective even if you only know how to hit 4x.
As per the spirit of parent's question - either you're assuming something impossible, or you're setting a goal to achieve something that is possible (in which case why haven't you scoped it out clearly & sanely).
I think the analogy to a sprint plan is perhaps misplaced: the point of an objective is not to break down the work for planning purposes but to capture the strategic imperative.
Instead it’s that you set targets in the various key results, normalize them to a 0-1 scale, and if you’ve achieved an average of 0.7 over all of the key results, then that would still be a measure of success.
We do the latter and there is deep suspicion if you are hitting 100% on your OKRs. I always thought of them as signifying direction versus destination, is this incorrect?
Over the past 20 years that describes the vast majority of my goals. That's how you get paid big bucks - by taking on goals you don't know how to achieve, and then achieving them, or at least making a good enough try. Colloquially this is known as "problem solving", and hard stuff is expensive.
If you're following this advice, you are either purposefully choosing goals that you do not know how to achieve, which is a problem, or purposefully choosing goals whose achievement relies on way too many externalities over which you have little control, which is a problem.
I'm not saying external factors shouldn't be considered, or that we should only set goals that are within comfortable reach.
Rather, I'm saying the uncertainty should be accounted for differently. It should be baked into our goals, not treated as if it only matters at the OKR level.
Imagine if you were to plan a sprint, and your story points did not factor in uncertainty at all. Then, you committed to a sprint size that also did not take into account uncertainty. But your stakeholders agreed that a 30% sprint failure rate was acceptable.
Now imagine baking in uncertainty into your estimates and then committing to a sprint size you can realistically hit. Add stretch goals if you want. Doesn't that seem more sensible?