My Mower Is Leaving a Strip Of Grass Down The Middle

I was in to my local Sears the other day and a customer came in looking for new blades. I asked him if the mower had been leaving strips of unmowed grass? He stated, “Yes, It leaves a 4 inch strip of grass right down the middle. This thing mows terrible! I’m about ready to sell it and get a different brand.”

He then purchased a new set of blades and I asked him if I could have his old ones. He said yes, and after he left I took this picture.

Blades

Can you tell me why he was leaving a strip of grass?

  1. sharpened so much that the ends wore down and pushed the grass out of the way