In any big encounter you will often hear managers say it is the "fine margins" that decide a game of football.
Sometimes it is luck. Sometimes it is individual brilliance. But on Saturday it was Sonia Bompastor's bold decisions that helped Chelsea beat Manchester City 1-0.
The top-of-the-table Women's Super League clash was as intriguing as you would hope it to be and both managers needed to be on their toes.
Chelsea boss Bompastor "took responsibility" and brought off struggling defender Kadeisha Buchanan 12 minutes in, and it had the desired effect.
City striker Khadija Shaw was not able to get in behind like she had done in the early stages, and Buchanan's replacement Veerle Buurman shone.
Was it a tactical substitution or was Buchanan injured?
When the fourth official's board went up showing the number of the player Buurman would replace, there was confusion from Chelsea players.
It was clearly not planned, nor had Buchanan asked to come off. There was no apparent injury as she jogged off and she was clearly upset, heading straight down the tunnel.
Asked to clarify the situation, Bompastor said: "Yesterday in training she got a knock to her head in contact with a team-mate but she was fine.
"She was fine in the evening and we assessed her again this morning and everything…
