Tenhou is rigged though. IIRC, if you are a non-paying member (and possibly use a non-Japanese IP - a claim I haven't verified), the game will steer you towards a maximum of 25% 1st places. I have seen good (non-paying) players with thousands of games and they did indeed reach only that percentage. Of course, there are ways to minimize the rigging (basically never riichi if you are 5-dan or higher) but those only help so much.