'one-to-one' vs 'one-on-one'

The cooking competition will be conducted as a one-on-one contest up to the final. However, the last assignment/challenge of the final will be a group showdown that...

(X) every dropout of tournaments comes on.— I have no idea what this clause means, but it is wrong. Please explain more.

1. Those going out of the tournament in each round will be the final opponents for both finalists. The last assignment of the final will be conducted as a one-on-many contest. That's what I tried to say.

2. Are 'one-to-one' and 'one-to-many' not natural? Or, originally you don't use those words?

lucas21cAre 'one-to-one' and 'one-to-many' not natural?

'One-to-one' is fine; it is an idiom. 'One-to-many' is not; I presume that is your coinage.

lucas21c Those going out of the tournament in each round will be the final opponents for both finalists.

And that is a very strange procedure indeed! Does that mean that ever

1. Actually, no. All participants but sixteen competitors will be eliminated from the tournament in the preliminaries beforehand. So, only 14 people can be the opponents for the two finalists. Could you tell me how I can convey that thought rightly?

2. Is 'one-on-many' also wrong and coined word?

lucas21c1. Actually, no. All participants but sixteen competitors will be eliminated from the tournament in the preliminaries beforehand. So, only 14 people can be the opponents for the two finalists. Could you tell me the right sentence that I can convey that thought?

Then I see no point in the competition, actually. However, just say that 'all registered

Then 'group showdown' is the right word that can express what I try to say? I wonder whether it can mean the contest that one competes with every one else. Each finalist must cook better dishes than all other 14 cooks in the final, who once lost and already went out of the tournament. That is to say, how to win the game is not like WWE Royal Rumble.

lucas21cThen 'group showdown' is the right word that can express what I try to say?

That sounds clear and appropriate to me.

lucas21cI wonder whether it can mean the contest that one competes with every one else.

Yes, that's what it would mean.

Then can I correct my second sentence like the following ones?

........However, the last challenge of the final will be a showdown with all participants already knocked out of the tournament. To survive in the stage, each of two finalists must cook better dishes than the other 14 cooks who want to get revenge.