If there was one rule you could change in cricket what would it be?

I have 2 rules for change:

1. The overthrow that hits the batter, the ball is deemed dead so batters cannot run extra runs, but if the ball makes the boundary its 4. Contradictory!

2. We need a 5 run option, without overthrows. So, if the ball goes over the boundary on the full but is touched inside the field of play by a fielder and a catch is not completed for a dismissal of the batter, then it is only 5 runs scored. If you want 6 runs hit it over the boundary untouched.

The umpires call on DRS reviews.

It should be irrelevant if reviewed using DRS. you either rely on technology fully or you don't.