Seems CL needed to make a change for the sake of change so they decided to offer search options Newest Relevance and Price with Relevance as default when you search in All for Sale.
I just spent some time going back and forth on their feedback forum about making the default newest...to no avail.
Here in Denver the highest relevance ad in my Sewing Machine search in All for sale is this one:
http://denver.craigslist.org/art/4164675772.html
Nice machine - fair price
Lowest relevance on the front page - first 100 listings -
http://denver.craigslist.org/atq/4150078924.html
Lowest relevance overall - over 500 deep - is this Pfaff Industrial
http://denver.craigslist.org/hsh/4163197752.html
You can still select newest but you have to do so every time
I'm beginning to wonder if some AHCA coders haven't jumped ship and gone to CL?