In two weeks there will be shown new stuff about DQxi (and i think we will get a release date for the game, should release before may, 27th)

http://gematsu.com/2016/08/dragon-quest-xi-confirmed-nx-simultaneous-launch-ps4-3ds-versions-suggested

but i wonder who will win this race in japan (and worldwide), all two are know to be the best games in the jrp genre...

I dont think any jrpg - or rpg in general - sells as much as DQ does in japan.
I don't think it will sell as much in western countries.
So, the usual, basically.

In Japan dragon quest wins but worldwide final fantasy

What the two other guys said...

Wait...they will show more of DqXI in two weeks???? YAAAAASSSSS finally!!!!!!!!!!!!!!

In Japan easily DQ. WW it could be an unfair race since it will also be out on the Switch which FFXV isn't.

Well heroes sold like 600k on ps4/ps3. You'd imagine a mainline DQ game would sell a million.

Now will FFXV sell a million in Japan? It could but not guaranteed.

DQ should do better in Japan, probably FF for worldwide

Ff15 will win worldwide. It might do better in japan as well because DQXI will also be on the switch.

DQXI will do better in Japan, Switch or not.

1. The handheld demographic will just buy the 3DS version being developed.

2. Dragon Quest sells amazingly well in Japan. In the millions. It has since it rose to popularity decades ago across Nintendo consoles, Sony consoles, and Nintendo dedicated handhelds. It could release on the NeoGeo and Japan would find a way to make it a million seller.

In the end, like everyone has parroted, FF15 is going to take the worldwide numbers. It simply sells much better everywhere except Japan, and it even does okay in Japan even though the series has become far more Western focused this past decade in particular. DQ XI is still going to sell very well in Japan, but will have at best average performance globally.

Coming back to the Switch for a moment, honestly, releasing the game on it doesn't make a ton of sense. People who want a handheld version are already getting one on a system that has way better handheld battery life than the Switch will. People who want a home console version will just pick up the PS4 version, helped by the fact that Dragon Quest is a system seller in Japan and the PS4 has really been picking up steam this past year in the Japanese market. The Switch version falls in this weird in between where it won't shine as much as the PS4 version (particularly if a Pro patch comes with it), will release on a console in its infancy while the PS4 has plenty of titles that appeal widely in Japan at this point, and won't grab the handheld audience that has likely already pre-ordered the 3DS version in droves.

Which market is the Switch version going to capture, exactly? And considering the Japanese will happily play phone RPGs to oblivion, the more power than a 3DS angle probably doesn't mean much.