A chain ring with 43t, 47t or 49t gives the same number of skid patches as the number of teeth on the sprocket.

I just now put a 47t chainring on my Pista, with a 17t cog, for 72.7 gear inches.
I didn't do it for the skid patches (I don't know how to skid) but rather because I wanted that specific gear inch.

Interestingly, I noticed I could put this chain ring on the outer position of the Sugino RD crank, and it looks 1000% better.
I flipped over the EAI sprocket, so the flange faces inboard, and I now have the most perfect chainline imaginable.
I mean perfect.
This didn't move the pedals, which leaves me with the same Q-factor or "tread" (as Sheldon puts it) as before, and so I can't think of any negative to this.
Looks good.