I've read that, at least theoretically, white has a larger advantage in 9LX as compared to chess. (See appendix.) This seems to be assumed in practice to the point that in some 9LX tournaments, such as the inaugural FIDE 960 world championship, they have players play both colours for any given starting position.
To even begin to talk about that white has more of a practical advantage, I think we should have some statistics that show there is a higher winning percentage change between white win and black win in 9LX as compared to standard. (Then afterwards we see if this increase is statistically significant or not.) But actually 'it's the reverse'! The winning percentage change is lower! See here (and hopefully here later on):
in standard, white has 23% advantage against black: (39.2-32)/32=0.225, but
in 960, white has only 14% advantage against black: (41.6-36.5)/36.5=0.13972602739
(By advantage i mean percentage change between white win rate and black win rate)
In particular those are statistics based on engine games. My thought is that these statistics show how far theory and practice are here given that even engines, under time pressure, do not make the most of the white's 1st move theoretical advantage.
Question: What's going on? What's the basis for all this practical/theoretical advantage in 960 or at least for the both colours thing in 960 tournaments (perhaps it's not about white's advantage or perhaps they're just going on the theoretical advantage given lacking data on practical advantage or something) ?
Guess: Wait I think I just figured it out. Even if in 9LX white has a lower advantage (again, percentage change between white win rate and black win rate), say, in the above case of 14% vs 23%, white still has a higher win rate like 41.6% vs 39.2%. So, like, white's comparative advantage (lower percentage change) to black is decreased, but white's absolute advantage (of higher win rate) is increased...?
In this case I'd like to submit for consideration that comparative advantage be used as a counter-argument to absolute advantage in saying they must play both colours in 960 tournament or something, but I guess I'd save this part for another post and perhaps not on stackexchange.
Appendix on white's theoretical advantage (I actually didn't think I needed to cite because I thought this is why they do the both colours thing)
From here (Why isn't Chess960 the standard?):
Another problem with Chess960 is that some positions are more unbalanced than the traditional starting position. While some positions are also more equal, there are a few positions which start with more than twice the "normal" White advantage.
There are some positions where White has a statistical chance to win of more than 60%. That's 6-7% more than standard chess.