Dice can be Weighted 26 Different Ways ...

Below is a chart from page 15 of the 1927 book "How to Control Fair Dice​"​ showing how dice can be unbalanced in 26 different combinations -- how do we know which imbalance we are playing with today compared to tomorrow.

If you worked in Casino Risk Management, you would know exactly which dice combination gave you the best profit margin compared to balanced dice.  Also, to prevent customers from taking advantage of a certain bias in dice, Casinos are changing the bias from one shift to the next.  Even after a hot roll, the dice may be changed immediately to a different bias.  Why would casinos ever need to change dice so often if all dice were created equal ?!  According to the Nevada Gaming Commission, dice are so much more durable now that they can be used for more than 24 hours without showing discernible wear.

We are finding more Casinos using a stick of dice that has several different loads - that not all dice in the same stick are equal. How do you know which 2 dice loads you have just picked up to roll with gives you which combination of numbers ?!! ... Is this the reason you just rolled 4 hardways on your first toss but you cannot even roll a hardway on your 2nd toss because you're using 2 different dice with different probabilities !!

The 2 certain dice that you're using on your 1st toss may produce a 25 roll.  However, the 2 dice you picked out the 2nd time may be unbalanced differently and assist in a PSO or much shorter roll with your same set on the same table.  It's harder to maintain consistency if you are not using the same equipment.