I wanted to confirm that my statement was accurate, so I found an example. Last July...
* Statement 7/10/2015
Balance $698.84
Points $32.26
7/13 Made payment $698.84
7/30 Bought car and put $982 on credit card
8/5 Made extra payment of $1300
* Statement 8/10/2015
Balance $807.96
New Points $41.07 (for $2107.96 in purchases, $1998.84 in payments)
Points $73.33
Plus, for the teeny tiny difference it makes, I redeem points for a deposit in my bank account, never as a statement credit, since you don't earn points on credits :)