Ideas for a draft lottery format?

[BeefSandwiches]

My league voted to have an NBA-style draft lottery for teams not in the playoffs and I am putting together some guidelines for how it works. The NBA uses 1000 chances and divides them up on a weighted basis between the 14 non-playoff teams using their W-L. I have four non-playoff teams and I am trying to find a fair way to divide their chances for the top pick and here is what I came up with:

20 total chances
Worst - 9
2nd worst record - 6
3rd worst - 3
4th worst - 2

Does this seem fair?

[RCR]

In the context you have, those odds seem pretty fair. However, I don't at all like that teams may "tank" the last game or two for increased chances at the first pick. Wouldn't the 4 teams rather play their way through a consolation ladder for the first pick? It works great in our league and actually makes the bottom teams play out the string competitively for a 25% chance at the first pick.