Manchester City boss Roberto Mancini has defended his tactics after a second scoreless draw on home soil in four days.
On Wednesday, City failed to find a way past Manchester United and on Saturday afternoon it was the same story against a Birmingham outfit hovering above the drop zone but committed to blanket defending the hosts were unable to get past.
"I am frustrated as well," he said. "I wanted to win. I don't want to draw or lose."
Carlos Tevez did have a first-half effort ruled out for handball and James Milner's shot was kicked off the line by Stephen Carr at the start of the second period.
But disenchantment in the stands grew when Tevez was replaced by Gareth Barry in the final stages, forcing Mancini onto the back foot.
Mancini added: "Carlos has had a little injury for two or three weeks and I felt if we took off that player we might have more chances to score.
"But if you think I put four strikers on and we score four goals, it is not true.
"All supporters are like this, in England and Italy. I must think like a manager. We can play wide, get the ball into the box, then we can score.
"Supporters just think why don't you put more strikers in the box, two, three, four, five."
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