In an effort to surprise Birmingham, the formation changed for City into 1-4-5-1. On paper it should work well, allowing Hamer and Shipley to play higher, bringing Kelly into the fold and holding the shape of the team together, but it lacked width with the personnel filling the 5.
A line-up lacking width with no outward wingers in the game would mean a game plan for setting up to control the tempo and possession. This is a game Coventry would have gone into with an expectation of a result and explains the line-up with expected control. You could see this early on as Coventry played mostly within the Birmingham half, allowing Kelly to get on the ball and push players in behind the midfield line. Shipley and O'Hare took up advanced positions which would provide support to an otherwise isolated Walker:
The issue then comes, as it has done all season, with leaving center backs isolated and needing to play more hopeful, risky type passes. 5 centrally, as it really worked out, should provide enough overloads for Coventry to play through a relatively low press as you saw from Birmingham. However, a common trend was to get up the field, without the ball, waiting for these types of passes to break the Birmingham press, and this pass resulted in McCallum getting hit in the air and winning a freekick. Not the ideal way to build up, but also not ideal for an isolated full back to win a header:
As the first half wore on, Coventry failed to really break Birmingham down in any meaningful way. Here is a moment of transition (left image) and Sheaf playing square to Hamer, with space ahead of him and 6 Birmingham players ahead of the ball. The right image is 9 seconds later and the wall of Birmingham, players we faced often. Dabo has the ball, looking forward but the 5 Coventry players in the picture are either in a flat line or have a shadow, moving away from goal, hence not really threatening.
According to whoscored.com Birmingham had no significant strengths or style of play in this game, yet they will likely feel the most frustrated at leaving with just a point. Jutkiewicz was a threat and in both halves would have backed himself to score the chances he missed. Birmingham would also push up when they had the ball looking to play in one defined way. This meant pushing Coventry backward by attacking with a front 4. The arrow shows the ball, for Colin, the RB, and how it pins McCallum back. Marosi easily picks this up, but the demand on the Coventry full-backs to then get forward and join the attack is too much. So, Coventry wasting possession resulted in the attacking trend of Birmingham pinning Coventry's outlet players deeper.
The images show the resulting pinning back of Coventry's outlet players (McCallum and Dabo), which resulted in long balls to an isolated Walker and inevitable turnovers as the only real chance he created was with his chin:
You can see no support within 20+ yards of Walker, and the ball 30ft in the air.
Reinforcing the view of Coventry's overthinking manager, as he tried to surprise Birmingham, he surprised his own players. Dabo, the first image, playing deep and long from a position that is usually held by a CB, allowing him to occupy the open rectangle. The same issue for McCallum in picture two with the ball at his feet and no outlet after a switch of play means an attack killing inside, backward pass.
This final image on the shape should explain everything from above, with regards to shape. I actually think the midfield 5 should have controlled this game more, but a refusal to play centrally explains flat attacks/long balls/no wide outlet:
On 67 minutes the substitutions happened and my thought was that now we've stifled the game for long enough, it might be time to go for it somewhat.
Biamou for Shipley meant two strikers.
Ostigard on for Sheaf meant 3 at the back.
Kelly would still hold, but the back 3 and support meant that Dabo and McCallum could provide the outlets we were begging for.
Then Hamer and O'Hare supporting Max and Walker.
The shape was in theory in favor, but it created no more and no fewer opportunities. On the other hand, it allowed Birmingham to find a foot in the game. I think due in part to the leash being off of Coventry. In this final image, you will see what a shape and mentality change can mean. With Coventry pushing forward and hunting for the ball after a turnover (whoscored.com also noted an attacking strength for Coventry was winning the ball back) left space that Birmingham never really capitalized on. Here you see another of those examples and whilst they didn't score, perhaps the tactical shift should not have been made and a maintained focus on closing the game out should have taken precedence. Especially given the Coventry success rate for conceding at the end of games and losing points.
Within the last 10 it looked like Birmingham were going to steal it, just like Watford did, and Forest before them. Coventry held on, but it shouldn't have come to that. My thoughts:
Either change the shape and personnel earlier in the game for balance and organization
Make substitutions relative to the formation and situation and reduce the risk.
We stunk the game out after a bright start, so doing so for the last 20 minutes would have been just fine. You could argue that we did that anyway, but we certainly did so with more risk and definitely no sign of reward.