Hex 13x13 vs. 19x19: Game Depth

I've just recently started paying more attention to Hex, and playing a few games, and I noticed something curious.

The spread of ratings in 19x19 Hex is much smaller than 13x13. Why is this? At first glance, it seems that it ought to be larger, since a larger board usually should increase the depth of the game. Is it just more poorly understood? Is it too complex to get good play? Or is it an artifact of fewer games and a rating system that takes too long to adjust?

I think your last suggestion explains the large majority of the difference: it's an artifact of fewer games and a rating system that takes too long to adjust.

I agree with Ignatius. Moreover I think the ratings from 13x13 are proportional to 19x19 playing strenght as well.

Besides fewer games, there also less number of players. Perhaps some are bored by the increased length of the game.

Fewer games also cause poorer understanding... so the real question probably should be "would ratings be more spreaded out if there would be more games?"

And by the way i think the answer is yes, there would... probably even more than 13... indeed we should play 19... but it's so hard and nobody has time to deal with it... :)