It's important to note that these are only rough guidelines and the strength of the backup as well as the quality of the opponent are crucial factors. (sportsinsights.com)
Also, keep in mind that these are just rough guidelines; if you feel that milk is no longer good, don't risk it. (momtricks.com)
I think as a very rough guideline, 5 % to 10 % is probably a good touch point. (seekingalpha.com)