Using the data from whoscored.com I've created my own version which just plots % attacked along the left and right hand sides. As the total for left/right/middle equals 100% you can infer the proportion attacked down the middle by the relative left/right values.
|Man City and Chelsea figures same as average split overall: 36% Left, 35% Right, 29% Middle|
There are a few teams however who stand out as being different to the rest:
Blackburn - Slightly above average along the left, a long way below average along the right, having the second highest proportion of attacking along the middle
Fulham - The mirror image of Blackburn with average on the right, way below average on the right and the highest proportion of attacking down the middle
Everton - Average along the right, a long way above average along the right so therefore below average through the middle
Wolves - Heavily left sided and slightly under average on both right side and through the middle
Swansea/Stoke - The mirror image of Wolves, heavily right sided and under average on both left side and middle
Although Swansea and Stoke for example have similar preferences for attacking sides, this will manifest itself in different ways. For Swansea, the Rangel - Dyer combination along with Williams' diagonal balls from the left side of defence results in a large proportion of attacks along the right.
Stoke are not just a set-piece team but it forms the biggest source of their goals: 45% of Stoke's goals have come from Set Pieces (which excludes Penalties) compared to the league average of 24%.
If you follow the logic that you want to maximise set pieces then you want to put the ball long and relatively close to the touch line to maximise the chance of a corner/throw in or a foul from any challenge for the ball.
Why so much down the right hand side? My theory would be that as the majority of footballers are right footed, having a set piece on your right hand side makes it easier for an attacker to kick the ball goalbound compared to a defender having to clear the ball.
Also, for a defender to get there first, their body angle is likely to result in a clearance to touch (and another set piece) rather than a clearance down field.
It might not please the purists but it's generally pretty effective as I had to witness as Stoke beat Swansea 2-0 at the Britannia with both of the goals coming from set pieces from attacks down the right hand side (from Stoke's point of view), one from a corner, one from a throw in.