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Fun With Quarter-Season Performances

Posted by Neil Paine on September 27, 2010

As part of Friday's post about the 2011 Heat's possible '07 Patriots connection, I had to run a little query splitting up every team's per-game point differential by each quarter of their season, and I thought we could make some use of that data today as well. To win 60+ games in today's NBA, a team needs to win 73% of its games, and that typically requires an average PPG differential of +7. This doesn't necessarily mean they played like a +7 team all season long, though -- if we break the season down into fourths (including playoffs), we find that only six teams in NBA history have ever played like a +7 team at every stage of the campaign:

Year Team 1stQ 2ndQ 3rdQ 4thQ
1971 Milwaukee Bucks 11.67 14.83 15.08 8.75
1972 Los Angeles Lakers 13.04 12.50 8.13 9.88
1972 Milwaukee Bucks 13.43 11.74 9.61 7.75
1987 Los Angeles Lakers 8.96 10.08 9.04 10.64
1991 Chicago Bulls 8.21 7.16 13.08 9.68
1996 Chicago Bulls 10.24 12.24 13.08 12.20

Even for a 60-win-caliber team, it's tough to maintain that level all season, especially given the fact that playoff games drag your 4th quarter differential down with their pesky increased opponent strength. Here's how the 60-win teams of recent vintage did it:

Year Team rsW rsL 1stQ 2ndQ 3rdQ 4thQ
2010 Cleveland Cavaliers 61 21 5.00 7.39 9.26 2.13
2009 Cleveland Cavaliers 66 16 12.71 7.92 6.67 8.17
2009 Los Angeles Lakers 65 17 9.35 7.35 6.08 7.48
2009 Boston Celtics 62 20 10.38 9.67 4.58 1.04
2008 Boston Celtics 66 16 13.89 5.15 11.70 5.44
2007 Dallas Mavericks 67 15 3.59 10.23 10.45 0.82
2007 Phoenix Suns 61 21 6.43 11.61 3.09 7.00
2006 Detroit Pistons 64 18 8.68 7.96 4.80 2.72
2006 San Antonio Spurs 63 19 7.22 6.29 7.67 3.63
2006 Dallas Mavericks 60 22 4.12 10.38 5.54 2.63
2005 Phoenix Suns 62 20 11.96 5.42 4.08 5.28
2004 Indiana Pacers 61 21 5.33 4.60 6.21 6.04
2003 Dallas Mavericks 60 22 12.24 6.12 7.00 -0.54
2003 San Antonio Spurs 60 22 3.73 5.70 8.19 4.15
2002 Sacramento Kings 61 21 5.42 9.12 7.33 5.04
2000 Los Angeles Lakers 67 15 7.50 9.65 9.88 1.93
1998 Chicago Bulls 62 20 6.04 5.08 11.50 5.69
1998 Utah Jazz 62 20 3.28 8.19 8.08 3.12
1998 Los Angeles Lakers 61 21 10.39 4.25 7.21 5.71
1998 Seattle Supersonics 61 21 7.39 9.91 4.39 2.83
1997 Chicago Bulls 69 13 13.48 9.24 11.84 4.88
1997 Utah Jazz 64 18 8.92 5.81 11.76 4.58
1997 Miami Heat 61 21 4.08 6.20 7.04 1.00
1996 Chicago Bulls 72 10 10.24 12.24 13.08 12.20
1996 Seattle Supersonics 64 18 6.84 8.15 9.62 1.38
1996 Orlando Magic 60 22 3.26 3.79 7.78 5.42

As you can see, meaningless late-season games and tough playoff contests have a real tendency to put a damper on a team's PPG differential, even among NBA champions:

Year Team rsW rsL 1stQ 2ndQ 3rdQ 4thQ
2010 Los Angeles Lakers 57 25 8.73 4.31 2.00 3.11
2009 Los Angeles Lakers 65 17 9.35 7.35 6.08 7.48
2008 Boston Celtics 66 16 13.89 5.15 11.70 5.44
2007 San Antonio Spurs 58 24 9.72 4.23 13.28 3.27
2006 Miami Heat 52 30 3.15 4.23 5.38 2.67
2005 San Antonio Spurs 59 23 10.46 10.54 3.77 3.56
2004 Detroit Pistons 54 28 2.38 4.42 10.35 6.67
2003 San Antonio Spurs 60 22 3.73 5.70 8.19 4.15
2002 Los Angeles Lakers 58 24 8.52 7.96 5.04 4.54
2001 Los Angeles Lakers 56 26 3.21 1.72 2.67 11.88
2000 Los Angeles Lakers 67 15 7.50 9.65 9.88 1.93
1999 San Antonio Spurs 37 13 3.56 12.24 8.12 7.24
1998 Chicago Bulls 62 20 6.04 5.08 11.50 5.69
1997 Chicago Bulls 69 13 13.48 9.24 11.84 4.88
1996 Chicago Bulls 72 10 10.24 12.24 13.08 12.20

Still, while even very good teams will see their PPG differentials decline steadily as the season goes on (all-time 60 win teams typically lose 3.2 PPG of differential between the 1st and 4th quarters of their season), here are the teams whose +7 or better early-season performances really told us nothing about how they would finish the year:

Year Team rsW rsL 1stQ 2ndQ 3rdQ 4thQ 1st-4th
1978 Portland Trail Blazers 58 24 10.73 7.27 9.95 -5.50 16.23
1968 San Francisco Warriors 43 39 7.83 0.61 -4.70 -8.00 15.83
2003 Dallas Mavericks 60 22 12.24 6.12 7.00 -0.54 12.78
1996 Houston Rockets 48 34 8.32 0.83 -0.77 -3.52 11.84
1970 New York Knickerbockers 60 22 13.72 6.76 9.64 2.35 11.37
1991 Boston Celtics 56 26 9.09 8.39 4.70 -0.83 9.92
2010 Atlanta Hawks 53 29 8.39 1.43 4.65 -1.08 9.47
2009 Boston Celtics 62 20 10.38 9.67 4.58 1.04 9.33
1985 Boston Celtics 63 19 11.32 2.92 7.31 2.00 9.32
2004 Sacramento Kings 55 27 7.43 7.00 5.13 -1.88 9.31
1989 Cleveland Cavaliers 57 25 10.62 7.00 9.59 1.41 9.21
1999 Portland Trail Blazers 35 15 7.20 8.94 5.81 -2.00 9.20
2001 Utah Jazz 53 29 8.14 1.23 8.41 -0.86 9.01
1979 Washington Bullets 54 28 7.68 4.20 4.76 -1.23 8.91
1983 Boston Celtics 56 26 10.18 5.64 1.68 1.39 8.79
1950 Syracuse Nationals 51 13 12.00 7.16 6.37 3.26 8.74
1989 Denver Nuggets 44 38 7.05 -0.33 0.24 -1.59 8.64
1997 Chicago Bulls 69 13 13.48 9.24 11.84 4.88 8.60
1983 Los Angeles Lakers 58 24 8.83 6.29 3.92 0.24 8.59
2002 Minnesota Timberwolves 50 32 8.00 3.71 0.43 -0.45 8.45

Obviously, personnel changes can play a huge role here; the 1978 Blazers were cruising along, ready to defend their '77 title, when league MVP Bill Walton broke his foot and was lost for all but 2 playoff games. However, sometimes teams simply start the season playing above their heads, and they just can't sustain the hot streak... like the 2010 Atlanta Hawks, who went from playing +8.4 ball (the equivalent of a 62-win team) early in the season to -1.1 (the equivalent of a 38-win team) late despite very little roster shuffling.

And finally, let's conclude the post at the opposite end of the spectrum, with teams who whose +7 play in the 4th quarter of the season represented the biggest improvement from the 1st:

Year Team rsW rsL 1stQ 2ndQ 3rdQ 4thQ 4th-1st
2001 Los Angeles Lakers 56 26 3.21 1.72 2.67 11.88 8.67
1994 Indiana Pacers 47 35 0.21 3.16 2.13 7.80 7.59
1989 Phoenix Suns 55 27 3.87 6.42 8.61 11.46 7.59
1989 Detroit Pistons 63 19 2.21 5.80 7.48 8.88 6.67
1985 Los Angeles Lakers 62 20 4.40 6.48 11.20 9.38 4.98
1986 Boston Celtics 67 15 5.72 10.08 11.92 10.60 4.88
2010 Orlando Magic 59 23 5.83 4.29 10.67 9.83 4.00
1951 Rochester Royals 41 27 3.70 2.86 0.65 7.38 3.68
1999 San Antonio Spurs 37 13 3.56 12.24 8.12 7.24 3.67
2009 Portland Trail Blazers 54 28 4.36 2.64 3.82 7.64 3.27
1997 Portland Trail Blazers 49 33 4.00 4.91 -1.62 7.09 3.09
2004 San Antonio Spurs 57 25 5.96 7.04 5.26 8.83 2.87
1982 Los Angeles Lakers 57 25 5.04 4.83 2.88 7.42 2.38
1950 Minneapolis Lakers 51 17 6.20 4.40 14.35 8.52 2.32
1961 Boston Celtics 57 22 6.82 6.82 2.64 8.91 2.09
1996 Chicago Bulls 72 10 10.24 12.24 13.08 12.20 1.96
1980 Milwaukee Bucks 49 33 5.68 -2.14 3.50 7.57 1.88
2009 Denver Nuggets 54 28 5.92 1.88 1.42 7.80 1.88
1950 Rochester Royals 51 17 8.47 8.83 1.72 10.28 1.81
1987 Los Angeles Lakers 65 17 8.96 10.08 9.04 10.64 1.68

This isn't the first time we've had an excuse to marvel at the 2001 Lakers' dissociative identity disorder, and it probably won't be the last, but... wow. Only two teams have ever been +11.8 or better in the 4th quarter of a season, the '96 Bulls and the '01 Lake Show. The only difference between the two? The former played like a +11.9 team in quarters 1-3 of their season, the equivalent of 68 wins over 82 games... The latter played at a +2.5 level aside from the last 1/4 of their season, the equivalent of a mere 48-win team. Needless to say, no other team in NBA history has ever gone from a 48-win-caliber team for 3/4 of their season to GOAT levels for the final 1/4. It might be the single greatest instance of switch-flipping in sports history.

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7 Responses to “Fun With Quarter-Season Performances”

  1. Jason J Says:

    What was Shaq's SPM for 2001?

  2. Neil Paine Says:

    +8.9. Kobe was +5, Fisher was +2.5, Fox was 0, and everybody else was negative (especially Rider, Shaw, George, Madsen, Penberthy, & Lue).

  3. schtevie Says:

    Neil, as game pace changed quite dramatically over the time periods shown, how about showing the results for offensive efficiency rather than ppg?

    Also, if you could de-trend the results by presenting them as differences to the quarterly NBA averages, that would also help to provide a clearer picture.

  4. Neil Paine Says:

    Unfortunately, we only have game-by-game possession totals since 1987, so PPG differential is really the best I can do for historical game-level studies. Also, the game-weighted NBA average in any given quarter is still going to be zero.

  5. Anon x 2 Says:

    what about adjusting for quarter strength of schedule?

    Boy, those '01 Lakers sure were special! At least some of their 1st 3 quarters could be attributed to injuries.

  6. BSK Says:

    Why are you including the playoffs in the 4thQ?

  7. Schtevie Says:

    Um. 1987 and forward as a supplement is better than nothing....no?