The question is who does have better chances getting royal flush on 10 handed PLO playing 10 hours of poker ,or 9 handed NLTH for 120 hours of poker.
Thanks.

Are you comparing a total of 10 hours of nlh to 120 total hours of PLO or 100 hours to 120 or what?.

Seems pretty straight forward to me
10 handed PLO, 10 hours
vs
9 handed NLH, 120 hours

I wonder how wrong is the estimate of comparing P(royal in a hand of Omaha) to 12*P(royal in a hand of Hold'em)

How many hands per hour in each game?

If the OP or anyone is interested in these types of questions, I think the information is out there to, at a minimum, come up with a very good approximation. Assuming all hands go to showdown:

- calculate prob of one player getting a royal flush in hold-em per random deal (call this PH)

- calculate prob of one player getting a royal flush in omaha per random deal (call this PO)

- estimate number of deals per hour in 9-handed NLHE

- estimate number of deals per hour in 10-handed PLO

- calculate prob of anybody getting a royal flush in a random deal of 9-handed NLHE as 9*PH minus the prob of multiple people having royal flush on same deal (only way is if royal flush is on board, right?)

- calculate prob of anybody getting a royal flush in a random deal of 10-handed PLO as 10*PO minus the prob of multiple people having royal flush on same deal (this is impossible in omaha, right?)

- calculate prob of anybody getting a royal flush in 9-handed NLHE per hour

- calculate prob of anybody getting a royal flush in 10-handed PLO per hour

- compare over the time frames in question.

Cmon. Omaha gives you six two card hands. Holdem gives you one. Plus you can make a royal in holdem with one card.

12 hands per hours in PLO,28 hands in per hours on NLTH

12 hands per hrs in PLO vs 28 hands per hrs in NLTH ,

you must play both of your cards in NLTH ,like in PLO ,

who has the best chances of getting ROYAL FLUSH, playing 10 hours of PLO with 12 hands per hrs,or playing 120 hrs of NLTH with 28 hands per hour.NOTE must use both of you cards same as PLO 2 from your hand 3 from the board.

comparing, who has the edge getting Royal flush ,playin 10 hrs PLO with 12 hand per hrs,or playin 120 hrs NLTH with 28 hand per hrs.must use both of your cards same as in PLO.

yes