I think both are 1/1000. Similar to the "Monty Hall" problem, the probability of getting the prize does not change after the host deliberately removed one loser, which is 1/3. However, in "Monty Hall", you can choose to switch; hence, if you choose a loser at the beginning, you will win the prize after the switch. The prob of choosing a loser is 2/3, which does not change either. As a result, in "Monty Hall", the probability of winning with switch is 2/3.Both this problem and "Monty Hall" do not change the probability after the remove.