Interesting statistical nuance to consider in the draw is the order and format...Runner ups are unseeded and are selected first, then paired with one of the 8 seeded group winners (Although I don't quite understand how seeding has any bearing on the draw)...So the excel spreadsheet on odds are applicable on the first draw, after which the odds change with each selection that follows
Group winners
PSG
Barcelona
Dortmund
Schalke
Malaga
United
Juventus
Bayern
Runner ups
RM
Arsenal
Valencia
Shakthar
Porto
AC Milan
Celtic
Galatasaray
Procedure
Under the draw procedure, eight blue balls containing the names of the group runners-up are placed in a bowl. A first ball is drawn from the bowl containing the group runners-up. The team drawn is placed as the home team of match 1.
In accordance with the conditions of the draw, the computer will then show which group winners are eligible to play the runners-up of match 1. A bowl will be prepared with white balls containing the names of the group winners which are eligible to be drawn against the runners-up of match 1.
A ball will be drawn from this bowl to complete the pairing of match 1. (Again, where does group winners seeding come into play?) The team drawn is placed as the visiting team of match 1.
This procedure is repeated for the remaining matches.
So basically the odds for Barcelona are dependent on the runner ups that are chosen and the order...If AC is selected first, the odds are that we'll face them...Yet if Arsenal are selected first, Malaga is more likely to face them...Of course, if AC is selected first and we don't get them and Arsenal is selected 2nd, the odds change and change depending on who AC is paired with - it could increase the likelihood of Arsenal facing us or have no affect, depending on the selection
There are a variety of permutations...Unless RM, Celtic or Valencia are chosen first then we are likely to be paired with whomever is drawn first from the runner ups due to the high odds with the remaining teams as Barcelona is among the 2 highest outcomes for opponents with the remaining teams...Basically, unless RM, Celtic or Valencia are chosen early, we're likely (highest odds) to face whomever is drawn early