On the inside of the 9, there is no post there. It is a curved edge that is what shapes the device. It usually shows a small chip at first and then continues to crumble away. You can see the same event starting on the 5 on the date in the same direction. The dies were over used on the 1950's wheat cents. So we can see several events happening over and over. Same with the 4 on the date, but chipping in a different direction.