Wellington's plan was to distribute troops along the whole of Soult's line but make his main attack in the centre. Any breakthrough in the centre or the French left flank would enable the British to cut off the French right flank.
Wellington's plan was to position his forces along Soult's entire defensive line, while focusing his primary attack on the central sector. If the British were able to break through in either the center or on the French left flank, they could potentially encircle and cut off the French right flank.