The unwritten rules of tennis and why postmatch handshakes sometimes go awry at the US Open

NEW YORK (AP) — There’s been a lot of talk about the unwritten rules of tennis during Week 1 of this U.S. Open , whether it's the necessity of a “ sorry, not sorry ” raised hand after a let cord or the proper way to warm up with an opponent or the legitimacy of an underarm serve .

Another part of the game drawing attention — thanks to players' complaints about each of the above — is the postmatch greeting at the net, which usually involves shaking hands and, sometimes, a hug or kisses on the cheek. It would seem to be a simple act of sportsmanship, but every so often ends up going awry.