Most losses in NBA championships as a player:
W-L record -- Player name -- Championship year (* = won)
0-8 -- Elgin Baylor -- 59, 62, 63, 65, 66, 68, 69, 70
1-8 -- Jerry West -- 62, 63, 65, 66, 68, 69, 70, 72*, 73
0-5 -- Larry Foust -- 55, 56, 59, 60, 61
0-4 -- Max Zaslofsky -- 47, 51, 52, 55
0-4 -- Rudy LaRusso -- 62, 63, 65, 66
0-4 -- Steve Mix -- 77, 80, 82, 83
1-4 -- Keith Erickson -- 69, 70, 72*, 73, 76
2-4 --
Lebron James -- 07, 11, 12*, 13*, 14, 15
2-4 -- Wilt Chamberlain -- 64, 67*, 69, 70, 72*, 73
2-4 -- Mel Counts -- 65*, 66*, 68, 69, 70, 73
2-4 -- Danny Ainge -- 84*, 85, 86*, 87, 92, 93
5-4 -- Magic Johnson -- 80*, 82*, 83, 84, 85*, 87*, 88*, 89, 91
6-4 -- Kareem Abdul-Jabbar -- 71*, 74, 80*, 82*, 83, 84, 85*, 87*, 88*, 89
Lebron, Ainge, and Zaslofsky are the only players on this list to have not played for the Lakers.
Source : https://www.quora.com/Who-has-lost-the-most-NBA-Finals