On the interesting thread about raising the basket to 11 feet, some posters indicated that if dunks were eliminated, scoring would be much lower. I took a look at yearly NCAA statistics from 1955 to the present to see if they would show any correlation between dunks and scoring averages, and I also looked at the effect of three-point shooting and the shot clock on scoring averages.
[U]1955 – 1967: When dunks were allowed [/U]
Field Goal percentage increased steadily from 36.9% in 1955 to 43.8% in 1967. Scoring increased from 69.3 points per game in 1955 to 74.9 ppg in 1967.
[U]1968 – 1976: When dunks were no longer allowed [/U]
FG% again increased steadily from 43.7% in 1968 to 46.7% in 1976. Scoring increased from 74.9 ppg in 1967 to a high of 77.7 ppg in 1971 and 1972, and then decreased back to 75.7 in 1976. I would not have expected shooting percentage and scoring to have increased at all when players were not allowed to dunk the ball, but that is what happened.
[U]1977 – 1986: When dunks were again allowed [/U]
FG% continued to increase, but less dramatically, from 46.7% in 1976 to 47.7% in 1986. Scoring steadily decreased from 75.7 ppg in 1976 to 69.4 ppg in 1986. I would not have expected such a dramatic decrease in scoring, but that is what happened.
[U]1987 – 2013: When dunks are allowed, the 3-point shot and the shot clock added (1986)[/U]
FG% decreased steadily from 47.7% in 1986 to a low last season (2013) of 43.3%. We have to go back all the way to 1965 with a FG% of 43.1%, to find such a low percentage. Scoring in this period increased from 72.8 ppg to a high of 76.7 ppg in 1991, and then decreased steadily and dramatically to 67.5 ppg in 2013. We have to go back all the way to 1952, to find a lower scoring average, at 63.3 ppg.
This is a little misleading, because teams are shooting more and more 3 pointers, which lowers the over all FG%. In 1987, teams shot 9.2 threes per game, increasing steadily to 2013, when teams shot 18.1 threes per game. Removing the threes from field goals, the FG% inside the three point line was 47.9% in 1987, and 47.7% in 2013.
An interesting fact from the shot clock years is that Field Goal Attempts went from 57.0 per game in 1985 to 55.0 in 2013. I would have expected attempts to increase, not decrease. Back in the 1950’s, teams were averaging about 70 shots per game, which surprised me, but then I realized that even though much more defense was played on the West Coast, the rest of the country was largely playing the fast break offense.
Some of the decrease in scoring and FG% can be attributed to changing defensive strategies, and to the NBA robbing Division One of some of its best players, the weaker fundamentals of today, and the fact that there are fewer good players on average playing the game now. I say this, because in 1955, there were 162 Division One teams, and today there are 345 teams. So the talent pool is spread around, and many teams play with players not so skilled. Still, I think it is fair to say that dunking the ball does not necessarily increase a team’s scoring average or affect its field goal percentage by much, if at all. The reasons for allowing or disallowing the dunk are subjective, and have nothing to do with scoring more points per game. Nor does the dunk result in a markedly higher overall shooting percentage, and maybe lowers it a little.
Here is the NCAA’s reference for the stats above:
http://fs.ncaa.org/Docs/stats/m_basketball_RB/Reports/All-time%20Statistical%20Trends%20chart.pdf
[U]1955 – 1967: When dunks were allowed [/U]
Field Goal percentage increased steadily from 36.9% in 1955 to 43.8% in 1967. Scoring increased from 69.3 points per game in 1955 to 74.9 ppg in 1967.
[U]1968 – 1976: When dunks were no longer allowed [/U]
FG% again increased steadily from 43.7% in 1968 to 46.7% in 1976. Scoring increased from 74.9 ppg in 1967 to a high of 77.7 ppg in 1971 and 1972, and then decreased back to 75.7 in 1976. I would not have expected shooting percentage and scoring to have increased at all when players were not allowed to dunk the ball, but that is what happened.
[U]1977 – 1986: When dunks were again allowed [/U]
FG% continued to increase, but less dramatically, from 46.7% in 1976 to 47.7% in 1986. Scoring steadily decreased from 75.7 ppg in 1976 to 69.4 ppg in 1986. I would not have expected such a dramatic decrease in scoring, but that is what happened.
[U]1987 – 2013: When dunks are allowed, the 3-point shot and the shot clock added (1986)[/U]
FG% decreased steadily from 47.7% in 1986 to a low last season (2013) of 43.3%. We have to go back all the way to 1965 with a FG% of 43.1%, to find such a low percentage. Scoring in this period increased from 72.8 ppg to a high of 76.7 ppg in 1991, and then decreased steadily and dramatically to 67.5 ppg in 2013. We have to go back all the way to 1952, to find a lower scoring average, at 63.3 ppg.
This is a little misleading, because teams are shooting more and more 3 pointers, which lowers the over all FG%. In 1987, teams shot 9.2 threes per game, increasing steadily to 2013, when teams shot 18.1 threes per game. Removing the threes from field goals, the FG% inside the three point line was 47.9% in 1987, and 47.7% in 2013.
An interesting fact from the shot clock years is that Field Goal Attempts went from 57.0 per game in 1985 to 55.0 in 2013. I would have expected attempts to increase, not decrease. Back in the 1950’s, teams were averaging about 70 shots per game, which surprised me, but then I realized that even though much more defense was played on the West Coast, the rest of the country was largely playing the fast break offense.
Some of the decrease in scoring and FG% can be attributed to changing defensive strategies, and to the NBA robbing Division One of some of its best players, the weaker fundamentals of today, and the fact that there are fewer good players on average playing the game now. I say this, because in 1955, there were 162 Division One teams, and today there are 345 teams. So the talent pool is spread around, and many teams play with players not so skilled. Still, I think it is fair to say that dunking the ball does not necessarily increase a team’s scoring average or affect its field goal percentage by much, if at all. The reasons for allowing or disallowing the dunk are subjective, and have nothing to do with scoring more points per game. Nor does the dunk result in a markedly higher overall shooting percentage, and maybe lowers it a little.
Here is the NCAA’s reference for the stats above:
http://fs.ncaa.org/Docs/stats/m_basketball_RB/Reports/All-time%20Statistical%20Trends%20chart.pdf