what happens if in magic tournament other player draws 8 cards instead of 7?

what happens if in magic tournament other player draws 8 cards instead of 7?

Depends on the REL. At Regular, the player will receive a caution, then the judge will take one of the cards at random and shuffle it into their deck. At Competitive and Professional REL, they receive a warning, and the judge takes two of the cards at random and shuffles them in. Then mulligans are taken as normal.

i think judge should let you also draw an extra card to make it even

Well, what you think is not what happens. Ever.