I’m glad this thread got revived, as I would like to give moral support to @Professor_X. I agree that komi is too high for 9x9, at least for DDKs, but since you can choose to play white, or set a custom komi, it can be mitigated.Oddly enough, a compilation of more than 17,000 19x19 OGS games (Win rate by players ranks in OGS) showed that all but two ranks from 16k to 1d had a losing percentage as black. Doesn’t this suggest that komi is too high even for these people in 19x19?
In another thread (New way of deciding Komi), I pointed out that komi for 19x19 is, I think, based on pro games, so it is not logical to believe that it has equal validity for lower-level games. The weaker the skill, from pro to DDK, the less ability a person has to exploit the advantage of the first move. I suggested that the ideal komi probably exists on a sliding scale based on rank. This is similar to what @zedsdeadbaby argues above.
In a long interesting discussion in the chat a couple months ago, @thought argued, very cogently I believe, that the stats actually show 7 to be the ideal komi for 19 x 19 (and logically, komi should be an integer since there are no half points in the game). Consequently, the half-point tie-break distorts the komi from the start.
To come back to 9x9, let’s look at another avenue for analyzing this. Instead of considering komi as a proportion of total points on the board, consider it as a proportion of the winner’s score (not the difference). Let’s say, for argument’s sake, that 65 is the average winning score in 19x19 (and leaving aside issues of rank). Then the Japanese komi would be 10% of the winner’s score. For 9x9, my impression is that the average winning score is in the low 20s. If 22, a 6.5 komi would be roughly 30%. The 5.5 OGS standard would be 25%. That strikes me as very large. Even if you substitute different numbers, the point is that the practical limit on how many points can be scored is vastly lower in 9x9 and hence the significance of komi looms larger.