What's the purpose of a convex saw blade?

Question

I am new to this stuff, and it is my first time seeing teeth on the backside of a curved saw blade.

Answer 1

This permits (if you are adequately determined) starting a cut in the middle of a board, rather than starting from the edge as usual.

Most commonly seen actually used when starting a hole in the floor, for instance. Once you cut the full height of the blade you'd switch to cutting with the normal cutting edge, which will be much faster and less effort.

Of course using a powered hand-held circular saw is also faster and less effort, so fewer people are familiar with this "feature" on handsaws these days.

Answer 2

That curved part of the top of the blade is designed so you can cut skirting board when it is fixed to the wall.

So you don’t have to remove the whole length.

Also for cutting that waist high trim that protected walls from chairs in older houses - again when it was fitted.