Was a few days late on my weekly Saturday blade change this morning. Put a fresh Derby in my Blue tip & proceeded to drag what felt like a rusty knife across my face. Only did 2 or 3 swipes. Changed the blade, smooth shaving again. Had I changed razors, I might have thought it was the razor and not the blade. Had this been my first time using Derby, I might have thought the blade was garbage and never tried it again. All of this to say-if you try a new blade and it doesn't work well-just throw another one in the razor to be sure. I love the Derby. But sometimes a blade just doesn't come out right- any blade. Cheers from Knoxville!