What assumptions are being made? For instance:<p>- Is this assuming your competitors will not be making any changes or optimizations to their website?<p>- That the backlinks are from relevant sites or general content sites? What would be their page rank? Is page segmentation factored in?<p>- Is it assuming no optimizations are done to the site trying to rank? Meta tags only? Full optimization? If so, what would a full optimization entail?<p>That's just scratching the surface. It's too early yet to think of more (just woke up), but I'd imagine the list would get pretty long.<p>The Google algo is somewhat known, but still considered a black box, with many outside variables. That's why any true professional SEO would never make any guarantees on website position in organic search or time frame.