Since 361/169 = 2.1 and 361/81 = 4.5 approximately, I’d give n handicap stones on 13x13 if the rank difference is between 2.1n and 2.1(n+1), and n handicap stones on 9x9 if the rank difference is between 4.5n and 4.5(n+1). I know this is not the most accurate formula but it’s easy to understand.

Only thing I would modify is replacing

with

`A = S - ((komi - K)(1/(2K)))`

where K is the default komi in that ruleset (so 7.0 in NZD all standard sizes), instead of hardcoding it to 6.5.

Though the way I prefer to think of it is in terms of komi, not stones. So `effective-komi = komi + reverse-komi + (2 * komi * (stones - 1) * -1)`

where `komi`

is the komi for an even game, `reverse-komi`

is the points (positive or negative) added to that for handicapping, and `stones`

is the number of handicap stones (default komi is assumed; add a reverse komi of `komi * -1`

or `(komi * -1) + 0.5`

if you wish to play traditional stone handicaps)

I’m not sure if the OP is asking about handicap or komi. Just in case the problem is komi, I have found that below about 7k, the komi unfairly favors white. Above about 1d I don’t think that the komi is unfair, since play is closer to ideal. I haven’t noticed any problem with handicap, that I can recall. If this posting is off-topic, let me know and I’ll delete it.

Okay, finally posted the proposal I mentioned related to small boards. It doesn’t cover everything that came up in this thread—such as capping the handicap rank difference in small boards—but does reduce the 9x9 handicaps that seem to overly favour black.