Payouts ?

If a horse runs and it still has shares available to purchase, is the payout calculated on the actual shares sold or from the share offering allotment? It seems from my calculation the allotted shares! If the allotment why so? Does not seem fair to the Owners ? I am certain it would not raise the payout but by a few cents or at least until the full share allotment is sold. It would seem management should take the risk of not having not sold a full allotment of shares. They do offer a couple of hundred thousand over their purchase price for all expenses. Especially if they partner with another horseman i am sure they share the horse expenses with them. If not shame on them.