Here's a pretty awesome chart of the 82 game season that shows who won and by how much from DanielM at Dstats. 

The bars with a bold red tip (bars on the left side of zero) are losses.  Wins are bars with a green tip on the positive side of zero.

What makes these charts awesome is they adjust for how much rest each team has, where the game is played, and the relative strengths of the teams (as measured by full-season performance).  The Jan. 5th game against the Celtics shows up as a 'good loss' because the C's had a rest advantage and home-court advantage.  It doesn't help us in the win column but we performed well enough to have a chance at the end of the game, and according to the chart we played well enough to smoke an average team without advantages that night.

via Dstats

The trend line shows no real direction one way or the other to the season.  That may or may not be the truth of the matter, with the resting of players, rotation changes and injuries that should or shouldn't be factors.  But it does appear to fly in the face of the attitude that the Spurs faded in the second half of the season.