How would you attribute your acceptance tick if two or more good, but partial answers were given, i.e., none is complete, but their union is?

Do you have valuable experiences you'd like to share?

I'm currently facing this situation after having asked for a maximum of a parameter such that a parametrised inequality is still valid. Within few hours two elegant & sound answers were posted – thus easily keeping the Tumbleweed badge at distance – one showing that $\,r_{max}\leqslant 9\,$, and the other one proving the $r= 9$ instance of the inequality.
Needless to say that my upvoting has been exhausted, but the acceptance tick is still dangling in grey. And I'd guess that anyone reading carefully the whole post will be hesitant to formulate & add another answer.

Being pretty sure that this situation isn't a seldom one in general, I did – possibly without enough stamina – search for relevant meta posts. Could only find Accepting more than one answer and some duplicate of it, and Only one answer..., but both have a clearly different focus.

• This is really your call to make. In the worst case you can (mentally) flip a coin. You can also make a note to yourself to next time select the user who got the short straw this time. Nobody should feel bad. In particular if you explain it (not that you owe any explanations to anyone). – Jyrki Lahtonen Sep 28 '17 at 17:59
• Incidentally, not so long ago there was a similar question at MathOverflow Meta: What to do with a question answered in pieces? – Martin Sleziak Sep 28 '17 at 23:40
• @MartinSleziak What a coincidence within few months & Thanks for pointing to this worthwhile ref ! – Hanno Sep 29 '17 at 7:03