Z2C, you have brought to mind an interesting statistic. I have long argued that 'average' should not be used as the go to statistic when looking at a running back. Rather median should be used.
If a runner gets the following sequence 1 yard, 2 yards, 12 yards, 1 yard, 3 yards, 1 yards, 20 yards: that is a 5 yard average. However to me, this series of numbers would indicate an ineffective run game. Herein the median would be 2.5 yards
However, if the series was 5,4,1,5,6,4,8 and 7yards, it is still a 5 yard average but it is much more drive sustaining and better run game, as the median is 5.5 yards