This might be a bit of a long shot as to making draw "transparent" (depending on entrats because i havn't a clue of the numbers who enter a specific tournament. And a bit comical too without having to rely on PC's
Get a big Dustbin (wheelie bin in UK), fill that wheelie bin with wgt "unlimited free balls" or the equivalant cheap balls you could buy. Now this is the tedious part, write on say 4000 balls a number from 1 to four thousand, throw them all in the wheelie bin then get Icon or Pizza to dive in pick out a ball, and the number on that golf ball might be 678, so who ever is 678 in the tournament leaderboard gets the prize! (if there is 6 ties at that number putt all those 6 in a hat and pick 1.
But if i'm wrong and then there's up to 20,000 or more to pick from, get a bucket with 20 balls in and a bigger bin with a thousand golf balls with 1 to 1000 on them, pick one out of the bucket with 1 to 20, if it is number 16, then the winner will be the person's who come between 16 and 17 thousand on leaderboard so out of the bin with 1000 balls you can draw another ball with winners number, if you pick 678 then that winner will be 16,678 on leaderboard.
As for Lou (ivietris) post, that was well said, sensible and honest and a proper heads up to quash all the "conspiracy theories"