Whenever I'm comparing Tatum the first guy in my head is always a poor man's KD. KD is taller and (currently a much) better shooter. Tatum is a bit more athletic with a bit better handle, but nether to the point that the mid range game isn't necessary to his success. He's also got the wiry frame, with the hope he'll fill out a bit more than KD. When KD turns on the defense during the playoffs he's suddenly this like suffocating blanket on the perimeter who nobody can get around or shoot over with all that length and above NBA average athleticism for the size. It's not a perfect comparison -- I actually think Tatum has more court awareness than KD and makes better reads as a team defender -- but in terms of man defense that's what Tatum does to his opponents. If Tatum's on you and you try and shoot over him or get around, it's going in at well below your career rate.