Undefeatable?
Don't play dumb; I know you're smart.
I just didnt find it undefeatable
...as entry "Z" had posed ample competitiveness, but in all seriousness, given the tier of your hosting and the scope of your advertising, A and Z are gauranteed to steal victory in any logical or subjective competition held forthwith...unless you are harbouring a more devastating opponent in hibernation until the day comes when you should decide to wreak havoc on your audience, and awaken them in time for another contest. 
lol nope
Ah, but I think you may and not realize it--or be of the mindset in which it does not concern you at all.