To any sanma players, do you have advice on how to spot open tenpai / dama honitsu / chiinitsu?
It's very tricky as about half the time there won't be any suited overflow before they hit tenpai. At most, all you'll see is 1 or 2 innocuous looking honors. It's also easily disguised by early terminal discards in their suit.
Pic related is an example of readable dama that I'd fold against, even in last.