Thin is in; flat is where it's at; thin and flat is all that.
Recently, a puzzling development opened up to me:
Coarse edges, in some circumstances, are better for push-cutting than polished edges.
Bishop Stamp recently asked if my new, super-sharp kitchen knife could push-cut through the skin of an over-ripe tomato. It couldn't. It would balance on the tomato's skin until a barely-perceptible draw was performed. At that point, it would drop as though it were a guillotine and fall through said tomato, but the initial perferation required a pull cut.
Failure thought I!
Recently, I applied interesting and exciting abrasives to that knife and made the edge thinner and more polished. The draw needed to initiate the guillotining was even less, maybe 0.25mm, but it was still there.
Infinite failure thought I!
Then I went with tear-filled face to the sharpening masters: the Foodies. Joe told me that coarser edges push-cut tomatoes with greater ease (apparently, the micro-serrations sink into the flesh whereas the polished edge spreads the weight of the blade over a larger surface area able to bear its weight) and Maniacally skilled and maniacally tempered Dave said that the guillotine-effect first seen on the new edge and improved with further sharpening was the 'Wow Factor' he had described in previous writings.
Just as the thinning of an edge concentrates more force into the cut, so can leaving teeth on an edge. It's not counterintuitive if you consider how pointy teeth bite compared to rounded teeth, but it was a surprize for me nonetheless and allthe more.