Like a joke...
Blood Potency is a measure of the characters age and power, and is something of an indicator of time the character has spent awake. A vampire’s Blood Potency increases the longer the character remains active, whether they want it to or not. Like Generation, it can also increase through diablerie. Blood Potency stacks with Generation to form the characters effective generation. As effective generation increases, the vampire loses the ability to feed on animals (effective generation 6) and then mortals (effective generation 8). When a vampire enters torpor, however, their Blood Potency falls by one for every 25 years she remains asleep.
Blood Potency is not tied to the Blood Potency, or Generation of a vampire’s sire. It’s assumed that older Kindred have more potent blood, but again, a few centuries in torpor will thin a vampire’s blood to neonate levels.