8ft is for soft tip
I think the others are for regional variations and the old ladies oche lengths
I'm a little surprised that the Yorkshire darts oche length isn't there tbh
I remember watching the Frank Skinner show, and he came up with his theory (the bigger the handbag, the uglier the woman) and a clip came on from the Indoor League, with a very plain looking woman with a huge handbag, throwing a dart. Haha