The math of games is tricky business. For instance, assume in a game you need to roll a 3 or higher on 1d6, and you can reroll 1s. My observed experience is that in such situations nearly 50% of dice rolled yield a 2.
— Mike Mearls (@mikemearls) August 17, 2018
I recently saw someone attempting to buff GWM to work on 3’s and 4’s as well, not realizing that this would lead to lower results overall : D that's why it's a PLAYTEST stream!
— Mike Mearls (@mikemearls) August 17, 2018