Why multiplied offset(0.5) in the beginning?

[nce3xin]

Thanks for your sharing, but when I read the code, I saw a variable called offset has been defined, then all values in the input dataframe are multiplied by offset(0.5). I would be grateful if you can explain it a little.

[jfpuget]

Because this leads to better results. I am approximating SMAPE metric with a log transform of the target, and using that offset was better.