Paste everyone who entered. The ducks pick the winner, and nobody β including you β can nudge which one.
Why groups instead of one duck each? With 1,500 entries you'd need 1,500 ducks on screen and you couldn't see a thing. So everyone is shuffled and dealt into groups, and each group rides one duck. Every duck carries exactly the same number of people, which is what keeps it fair β if one duck carried fewer people, riding that duck would be an advantage.
Sometimes the numbers don't divide evenly. When that happens a few empty seats are added so all the groups stay the same size. If an empty seat somehow wins, the draw is simply run again β that's rare, usually well under 1 in 100.
Where the randomness comes from. The races are decided by a public random number published every 30 seconds by a worldwide service called drand. Everyone on earth sees the same number and nobody can choose it. We save the exact number with your draw, so afterwards anyone can look it up and confirm the result was not tampered with.
The races are a picture of that result, not the thing deciding it. The winner is worked out the instant you press start; the ducks then show you how it played out. Replaying a draw always shows the identical race.
Where your list goes. On this hosted site your entrant list is stored with the draw so the public link works for everyone. Running the offline copy instead keeps everything in your own browser.