Hello Peter:

petero2 wrote:My perft(14) calculation is now finished and the result is:

61,885,021,521,585,529,237

It seems reasonable given earlier estimates, but obviously needs independent verification.

Congratulations for this huge task!

There are some estimates, some of them quite old:

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```
61,803,489,628,662,504,195 by Joshua Haglund.
61,865,545,676,422,373,910 by Matthew R. Brades.
6.187e+19 by François Labelle.
6.18847822079403e+19 by Peter Österlund.
61,886,459,822,115,294,738 by myself.
6.188925e+19 by H.G.Muller.
6.18986e+19 by Reinhard Scharnagl.
```

If I am not wrong, these are the relative errors err_i = [estimate_i/Perft(14) - 1] rounding up to 0.0001%:

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```
Joshua Haglund's estimate ~ Perft(14) - 0.1317 % ; |err| ~ 1/(759.03)
Matthew R. Brades' estimate ~ Perft(14) - 0.0315 % ; |err| ~ 1/(3177.53)
François Labelle's estimate ~ Perft(14) - 0.0243 % ; |err| ~ 1/(4119.76)
Peter Österlund's estimate ~ Perft(14) - 0.0004 % ; |err| ~ 1/(258593.79)
My estimate ~ Perft(14) + 0.0023 % ; |err| ~ 1/(43026.49)
H.G.Muller's estimate ~ Perft(14) + 0.0068 % ; |err| ~ 1/(14635.29)
Reinhard Scharnagl's estimate ~ Perft(14) + 0.0219 % ; |err| ~ 1/(4557.58)
```

I hope no typos.

Ajedrecista wrote:I expect to be wrong in less than 0.01% this time. It is too soon but I think that Peter's estimate is the best one, followed by my own estimate.

I was far below 0.01 % of relative error! But I rightly wrote that Peter's estimate would be the closest one. Indeed it is superb... once again, just like with his Perft(13) estimate. Well done!

Waiting for independent verification... it will take a while.

Regards from Spain.

Ajedrecista.