Arsene Wenger felt somewhat vindicated after Arsenal defeated Manchester City 2-1 in the FA Cup semi-final on Sunday.
The Gunners boss went with a three-man defence for the second match in a row after it worked well in the Premier League against Middlesbrough.
While Arsenal had to fight from a goal down to get past City in extra-time, Wenger felt the decision to deploy Gabriel Paulista, Rob Holding and Laurent Koscielny together again paid off.
Asked if he should have tried this formation earlier, Wenger said: "Well, yes. I like your question, because it shows exactly what our job is.
"No matter what you do, even if you get it right at some stage, people say 'Why didn't you do it earlier?' It's like the opposite is right, is wrong as well. If you get your starting line up wrong, you change it at half-time, people say 'You see, he is a tactical magician!' because he changed the team at half-time.
"But they forget that we got it wrong at the start. So you can always judge on both ways.
"I think what I did is just to give a bit more security to a team who conceded three goals in the last three away games, at West Brom, at Liverpool, at Crystal Palace and at some stage even to focus on something different for the players recreates some confidence."
Asked if it is the bravest decision he has made this season, the Frenchman added: "I don't know. I'd have to look back.
"During the season I made some tough decisions this season. We have gone through a difficult period. I don't know, but it's my job to try to get it right.
"When it goes well, we are happy."