Senate races in order of likelihood of switching?

Where could I find a list of the Senate seats up for election in 2016 in order of how likely they are to change, so I can get some early idea as to what’s going to happen to the Senate based on early results? (Anyone familiar with the concept of “swing” in UK Parliamentary elections knows what I am talking about.)

There are probably a number of these; which ones are generally considered fairly accurate?

Huffington Post

538

Of those two, I consider 538 the most unbiased.