I sub my best players when i have good result advantage to protect them from injury or cards, but few times opponent almost made comeback (from 3-0 to 3-2). You should sub players with worst condition and player who does most of mistakes (read match comments)
I generally do sub players with worst condition or worst performers and after 70 minutes and they're usually defenders. I guess it's just one of those things. Learnt my lesson today.
ROMANBY VILLAGE FC (founded December 24th 2013)
Level 133
50 League
8 Champions/Elite League
4 Super League/Gold Cup
12 Cup
1 Super Cup