He scored 20 in 26. That's an outstanding ratio whether you like it or not. 36 goals the season before that, arguably the most important player in his team - fired his team to the title and to the CL final. Before that, played out wide and scored 20. 5 games into the season and apparently Lukaku is a better striker than him. I'm taking everything you say about Costa with a pinch of salt anyway, since you think Lukaku is a better player than him.