The pot is based on the number of entrants although I have seen Celebrity supplement the pot when the turnout is very low. The on board entry fee is $20 so there is no incentive to buy ahead of time. Also is the pot based on the total number of entrants? A bunch of preliminary rounds then the the highest 6 or 7 players complete for the prize. I figure the tournament is run similar to others I have been in on cruises. Does the $20 shown on the website represent any discount from the 'on the ship' price? Also on other lines I have been on, they would often have a 2 for 3 deal (buy 2 entries and get the third free).
I'm looking at some of the stuff that I can purchase pre-cruise and one of the them is an entry to the Blackjack Tournament.