A video about five very common chess mistakes at the beginner through to intermediate level that are really important to avoid (or at least to reduce!) if you wish to take your game to the next level.
01:00 - 04:23 Piece activity
04:24 - 08:51 Mindless trades
08:52 - 12:55 Attacking too early
12:56 - 16:33 The bishop pair
16:34 - 21:30 Pieces in enemy territory