I assume he's alludes to the patterns that you learn to recognise when you 4/3wide. For example, if you mainly 4wide, you will know that placing an O-piece next to a vertical S/Z-piece (that was used to plug a garbage hole, for instance) will flatten out that area, while a 3-wider might intuitively go for covering the outstanding protrusion with an L/J-piece in order to flatten.
*waits for jkwon to explain himself and reveal that I totally misunderstood his point*
Sandal that Stinks
Current 40L (Nullpo): 39.36s