David Brent
Midfield
26.84%The advantage may have been in "not scoring".
30 - 40% of goals in the championship come from set pieces.
Watching Boro practice set pieces would give them all they needed to know to help negate them.
Also Boro famously are crap at scoring from open play, so you stop the set pieces you probably stop them scoring.
(It could be after the fact bollocks - but there's been talk after this broke that a number of teams were surprised at how well Southampton negated their set pieces this season)
And again - the issue isn't "how did they benefit?"
The issue is they broke clear rules to try to gain a benefit - that's enough.