You are missing the point here. Technical analysis does help, but it won't guarantee wins if luck doesn't side with you. Luck is the most important factor here. No one can be 100% confident about their prediction.
This is why you rarely see the same person winning the contest twice or thrice or more.
Two predictions helps improve the luck factor for obvious reasons which is why literally everyone post two predictions(Not just one) unless they forgot to post their predictions in the specified time intervals.
Your analysis can give you idea of how it will perform in the coming days but again it's just a speculation as nobody can determine the exact prices at certain point of time in future because we don't have magic future ball.So yes you need to be lucky in these predictions contest that bitcoin prices come under your guess.
For sure the two predictions give you more chance and you have two different predictions so anyone won't miss this chance as there is nothing to loose about it if you make two predictions but a advantage for you.The good news is bitcoin prices rising again as we are entering $30k range so make predictions accordingly.