Aggressiveness is mostly determined by the blade exposure. Razors with more blade exposure are more aggressive.
If you have an adjustable, starting with lower settings is usually the best thing to do.
^^^ Great pic Boro! Worth a thousand words, lol
I'm pretty new to wet shaving and about a month ago I took the plunge and bought my first slant bar ( Merkur 39c ) I remember while waiting for it in the mail thinking "this is going to be way too aggressive" turns out its my favorite razor and gives me the smoothest irritation free shave with just 2 passes ... I guess my point is don't be afraid to try what some consider an aggressive razor, and remember .. Using an aggressive razor and getting a near BBS with just 2 passes is going to leave a lot less irritation to your skin than using a less aggressive razor and doing 3-4 passes
... again as with all razors, soaps, creams, blades, brushes, aftershaves etc -----> Y M M V
As for the matrix you are looking for, there is a table here at B&B, and a fairly recent one, that ranks various razors on an aggressiveness scale of 1-10.I currently have a Merkur 34C and have been contemplating getting a more aggressive razor, however, I have no idea whatsoever which razors are more aggressive or less aggressive. Is there any kind of a matrix or list out there that ranks least aggressive to most aggressive razors?