If you want to play the Scotch as White, you need to consider the 4th - Bc5 variation. Here 5.Nb3 has proved its worth. White removes the possibility of simplification from the position by the general exchange on d4. White can then build up logically, so that little concrete theory is necessary.
Taking on the Scotch with 4 - Bc5 is the first choice for all those who do not want to do the considerable amount of work involved in the Mieses Variation. Here, Black has the opportunity to seize the initiative. Particularly in the variations with an early black queen exploration, concrete mathematical skills are required.
Black players need to have something in their repertoire against the Scottish. And the set-ups with 4th - Bc5 are easier to master than the Mieses Variation.
Would you like to learn this opening? You can find specialised opening training courses here: Scotch