redirecting connections based on probability

[Bartosz Giza]

Hi,

I have to do such a thing like redirecting connections to port 80 based on 
probability. For example i need to redirect 10% requests to my web server and 
other 90% of requests should go to the original location.

I know that pf has probability feature but there is no probability option for 
rdr rules. I have tryied couple of methods that could work but they didn't :(

The problem is that rdr rules works on incoming packets so i can't use them 
dirrectly because i don't want to redirect all packets to different location. 

Could somebody tell me is such a thing possible in pf ? If yes please point me 
how is that possible.
Very thanks