Considering substitution strategies

I want to acknowledge the user's question about substitutions in a match. I should ask them for specifics like which match, team, or minute they are referring to. Then, I can provide possible reasons why substitutions can change the game, such as fresh legs, matchup adjustments, shape changes, mentality shifts, or using set-piece specialists. It might also be helpful to offer a deeper analysis if they share their lineup and the substitutions made.