Almost all modern oars are set to zero pitch at the oarlock so that you can rig using the pitch insert bushings. This was not always the case.

The shape of the macon blade was such that a much higher pitch was desired and the clever adjustable plastic oarlocks had not yet been invented.

To ensure adequate pitch, the oars were made with ample pitch built in. You could tell what side of the boat a blade should be on even if there were no numbers, markings or helpful red/green buttons.

This particular blade (late ’70s from Hungary, I think) shows this quite clearly. It measures on screen at about 4 degrees.