In all contests just like the captivating Capiz SEO contest, the anchorage of your blog post will always matter. It is a big factor in getting the perfect blend of all your links as well as all your effort for link building. If you know how to make your links look good in Google's eyes, you might want to consider a long yet good way of knowing which is to experiment on it.
I have quite a lot but it seems for me there is nothing better with link building giving your contest entry some kick when you use the main keyword itself which will eventually get dilluted as a certain time. So I bet that timing will always be the secret to getting there where you want your entry to be. If you know how to blend your timing with the diversity of the links that you need to push an entry over the others to the top spot, then you have what it takes to be there.