Perfect example of BTA there. Wallace has it out wide, BTA is making the run but he holds back about 4 yards behind the defender for no reason. Then as SOON as Wallace plays it he sprints andd he ends up being a yard or two short. Wallace signalled to him that he didn't make the run he needed.
He needs to have been right on the shoulder of the defender so when the ball is played he's got the extra yards he needs.