EXCLUSIVE CONTENT Get ESPN+ Upset rankings: Which top seeds might fall in Round 1?The Sixers might have to try to hold off the pesky Nets without Joel Embiid. Fernando Medina/NBAE/Getty ImagesKevin Pelton, ESPN Senior WriterApr 13, 2019, 08:26 AM ETClose Co-author, Pro Basketball Prospectus series Formerly a consultant with the Indiana Pacers Developed WARP rating and SCHOENE systemFollow on XEmailWhich first-round NBA playoff series are most likely to feature a win by the lower-seeded team?