W2W4 previews the weekend's Premier League fixtures and highlights five key storylines.
New faces in burgeoning rivalry
Since the start of this decade, the two most constant Premier League forces have been Manchester City and Chelsea. Both have collected two titles apiece, Chelsea in 2009-10 and 2014-15, City in 2011-12 and 2013-14.
This is not a historic rivalry, as both clubs only truly rose to prominence in the 21st century, both by virtue of heavy investment by foreign benefactors....