Some better finishing in the Dortmund game and they really should have thrashed you silly, same goes for Real Madrid, the "what if" game works both ways. Ultimately on the performances City were well below par. Real Madrid had 35 shots, 35, to your 10, with only 12 on target vs your 3... Dortmund had 22 shots vs your 12, with 10 on target vs your 7... and their chances were often brilliant and had a particularly awful day infront of goal they played you completely off the park, completely.
The critical thing isn't ever the results , but the performances and key this season has been Mancini's reaction to said performances.... all to often his reaction is, 3-5-2 sounds a lark, we haven't practiced it(apparently) lets do it to relieve the pressure. 10 mins later and a further goal down it goes back to 4-5-1/4-3-3.
But the reactions are getting worse, he's had a go at Hart for merely saying the truth, he's had a go at Micah basically saying, you're not a top player if you aren't perfect at a formation you've never played before.... because Mancini is a moron.
As the performances(if not always the results) have been going badly, Mancini's reactions are getting worse, it starts off with a draw, and a "oh well, that was unlucky", progressed to a "we probably would have won but for player X", to "maybe these aren't top players". How did Chelsea, Liverpool, 58 other teams do with a manager who starts making excuses, starts getting upset in interviews, starts blaming the players. Do they bolster the squad spirit and produce ever better performances, or do they start losing the dressing room and performances get worse?
Chelsea's current win rate is 80%, City's current rate is 60%, 2 points might not seem a lot, but on current form that will only increase, City had a 75% ish win rate last season, they aren't close.
As for playing well and being unlucky, very few non City fans see it that way, City have been putting in abject performances. they weren't good against liverpool(who also had more shots than City), weren't good against Arsenal, were horrendous for 45 mins vs Swansea and again it was Swansea's poor finishing that got you that win. West Brom, a team without particularly great players took the lead and managed 17 shots.
Anyway, the main thing is Mancini seems to be going the way of Benitez, he's making worse decisions, reacting badly, throwing strops and what happened last year. Outside of scapegoating your best player at the time(or most effective game winner) for, what your club decided was not warming up a second time, when it looked like he wasn't going to win he proclaimed the league over and spoke to multiple clubs about his next job.... rather than stick it out put every waking second into improving the team he was looking to secure his next big paycheque. Then Utd threw away the title and Mancini plays the "I love this club, would never leave, look I have a blue and white scarf" sucking up to the fans rubbish.
He lucked into the league with the best squad by a mile, the fewest injury problems by a mile and the biggest self inflicted wound by a mile.
