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Can I random walk myself to 2300?

I love this kind of experiments. Thank you!

I love this kind of experiments. Thank you!

I used to have a rating 2200 at bullet chess and I started playing my own nonsense b3, Bb2, Qc1, Nc3, Nd1, f3, g3, Nh3, Nhf2, 0-0 in every game. Now my rating is 2500, and if I play normally without that nonsense, I can reach max 2200-2300, my play strength didn't really go higher, so have I walked myself randomly to such a high rating?

I used to have a rating 2200 at bullet chess and I started playing my own nonsense b3, Bb2, Qc1, Nc3, Nd1, f3, g3, Nh3, Nhf2, 0-0 in every game. Now my rating is 2500, and if I play normally without that nonsense, I can reach max 2200-2300, my play strength didn't really go higher, so have I walked myself randomly to such a high rating?

my guy here pulling greek letters as excuse not to study chess, respect

my guy here pulling greek letters as excuse not to study chess, respect

While the monotonicity of tanh preserves the symmetry about R_real, and the drift guarantees a unique stationary distribution, I do not think that it is Gaussian. While there are a number of mathematical ways to try and show this, the easiest counter example is to probably just overlay the plot of your "analytic" solution with a Gaussian density with the same mean/variance (or just compute the L2 distance between them as functions over your support).

While the monotonicity of tanh preserves the symmetry about R_real, and the drift guarantees a unique stationary distribution, I do not think that it is Gaussian. While there are a number of mathematical ways to try and show this, the easiest counter example is to probably just overlay the plot of your "analytic" solution with a Gaussian density with the same mean/variance (or just compute the L2 distance between them as functions over your support).
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I believe if the drift is linear then the resulting distribution will be gaussian. The tanh function is probably close enough to linear over the range of interest (+-100) that you would struggle to see any difference.

(to see the linear case: if there is no restoring drift, then the limit distribution is a gaussian with increasing variance, this being an expression of the central limit theorem. A linear restoring drift is just a rescaling that doesn't change the shape.)

I believe if the drift is linear then the resulting distribution will be gaussian. The tanh function is probably close enough to linear over the range of interest (+-100) that you would struggle to see any difference. (to see the linear case: if there is no restoring drift, then the limit distribution is a gaussian with increasing variance, this being an expression of the central limit theorem. A linear restoring drift is just a rescaling that doesn't change the shape.)

@jdannan said in #7:

I believe if the drift is linear then the resulting distribution will be gaussian. The tanh function is probably close enough to linear over the range of interest (+-100) that you would struggle to see any difference.

(to see the linear case: if there is no restoring drift, then the limit distribution is a gaussian with increasing variance, this being an expression of the central limit theorem. A linear restoring drift is just a rescaling that doesn't change the shape.)

Agreed. The difference would mostly be in the tail behaviour. I only mentioned it because it was hinted they were trying to prove it was exactly Gaussian, which I dont think will be true.

@jdannan said in #7: > I believe if the drift is linear then the resulting distribution will be gaussian. The tanh function is probably close enough to linear over the range of interest (+-100) that you would struggle to see any difference. > > (to see the linear case: if there is no restoring drift, then the limit distribution is a gaussian with increasing variance, this being an expression of the central limit theorem. A linear restoring drift is just a rescaling that doesn't change the shape.) Agreed. The difference would mostly be in the tail behaviour. I only mentioned it because it was hinted they were trying to prove it was exactly Gaussian, which I dont think will be true.

Fun insights aside, I enjoyed the tone and the jokes of this post :)

Fun insights aside, I enjoyed the tone and the jokes of this post :)

The random walk resulting from the rating fluctuations has a mean reversal property and with some assumptions... I think this could be modelled as an Ornstein-Uhlenbeck process (https://en.wikipedia.org/wiki/Ornstein%E2%80%93Uhlenbeck_process).

Questions like how long before I hit a certain rating .... how much time/ many more games before I return to a some rating after a losing streak... can then, in principle, be solved analytically as function of:

  • The players current rating (R)
  • The players true skill level (R_real)
  • The target rating of interest

I think...

The random walk resulting from the rating fluctuations has a mean reversal property and with some assumptions... I think this could be modelled as an Ornstein-Uhlenbeck process (https://en.wikipedia.org/wiki/Ornstein%E2%80%93Uhlenbeck_process). Questions like how long before I hit a certain rating .... how much time/ many more games before I return to a some rating after a losing streak... can then, in principle, be solved analytically as function of: - The players current rating (R) - The players true skill level (R_real) - The target rating of interest I think...