Well you could work out the chance of winning compared to every post combined. You could also work out the chance of you winning compared to everyone else
Assuming that each post since post 1 will count to the raffle, here it is (including Excalibur)
Most people have less than 10 posts in here.
So, in total that is 413 posts. Ok.
The average is about 0.241307506053269. Uncomfortable decimals so...let's round it to the hundreths. Yay, 4th grade math!
I want to say that, sadly, people who have 1 post in this thread has a 0.24% on winning. ;w;