Mentioned in the session report that the WRC Chombo penalty is 8k points penalty. I apologise that I made a mistake on this. The penalty is actually 20. Anyway, here is a quote from the rulebook 2015.
Download Link – http://ooyamaneko.net/download/mahjong/World_Riichi_Championship_Rules_2015.pdf
CHONBO — When other players’ hands cannot continue normally. 20 points penalty and the hand is re-dealt. The point penalty is handled as described in the point penalty section. Riichi bets are returned to the players who declared riichi. No continuance counter is placed, and the dealer does not rotate. There is no “mangan payment”.
- If a chonbo occurs simultaneously with a win, the chonbo is voided: the offending player is not penalized, the winning hand is scored, and the seat rotation is resolved normally.
- If a chonbo occurs simultaneously with an exhaustive draw, there is no noten payment and no continuance counters are added. The hand is re-dealt.
Feng
Riichi Mahjong in Singapore 