Miley Cyrus & Sister Sit Courtside at Knicks-Cavaleirs Game

Miley Cyrus can't win 'em all ... she took an L in a family feud at Madison Square Garden, 'cause she was stupid brave enough to back the Knicks.

Miley and older sis Brandi Cyrus sat courtside for the Knicks-Cavs game ... getting some extreme closeups of LeBron James. Despite the Knicks sucking hard this year (they lost by 14 last night) Miley rocked a Kristaps Porzingis' #6 t-shirt.

Brandi knew best this time, since she sported a King James jersey. Still, give the freshly minted 'Voice' judge partial credit for sticking with Godzingis.