P57, the statements people have made about POT have not implied it is used in progressive staking or anything about winners being "due".

You are correct that it's known only after the race (same for strike-rate) but over the course of time one race isn't going to affect the figure dramatically. POT together with strike-rate gives you a sense of the type of bets you make and how profitable they are for you. This is useful knowledge when planning your betting approach and what you might expect over time, based on your past experience.

It is a far better indicator than counting the dollars in your wallet at the end of the day, where say you find yourself $20 up: if you've bet $1000 (2%POT) then you've just scraped out a profit and with that kind of margin you'd really need to know what you're doing in that risk/reward scenario. On the other hand, if you've bet $1 (2000% POT) then you'd probably consider that luck, or at least realise it's unlikely that level of profit will be sustained.

POT is simply the most appropriate measure of your profitability. Every business needs to know it's profitability, even in racing where the future holds uncertainty.