# problem with with data transformation

i use lets say log transformation to get better distribution and get better predictions in a regression problem and i do, but here is my problem, lets say without the log transformation i get an $R^2$ of 0.86 and with log transformation i get 0.89, so if i'm not wrong to get the real $R^2$ we should transform the predicted values back to their original distribution and when i do the $R^2$ becomes very close to $R^2$ i got without using the log transformation.

i'm not sure i'm right about doing this but if i am, then what is exactly the point to doing the log transformation?

And it is correct that you get the "first" R2 when you trasform back. In fact when you do a transformation you should always keep in mind that you need to apply an appropriate inverse function on the predictions (ex: log() trasform needs exp() on predictions).
So, for instance, variables related to money (like income and price questions) are often log transformed because we think about money in multiplicative terms rather than additive ones. E.g. If your salary is \$20,000 per year and you get a \$5,000 raise, that's huge. If your salary is \$200,000 per year and you get a \$5,000 raise, it's not so big.