Simple Question: What percentage of 1v1 ranked games are decided before the 100 unit mark?

I've been learning to play and I'm curious if I need to be able to handle over 100 units to be competitive. It really seems like a lot of games are decided at less than 50 units.

I wonder if this is a conscious choice by the attackers not to let the game get out of hand, or just the state of the game in general.

Thanks!