Birtles: Pace is key against the Blues
Because it is already in place.
If Nottingham Forest stick to the approach they have adopted in the last two matches, they will win.
It really is as simple as that.
Birmingham may have had their best start to a season in decades; they may be sitting in the promotion places at the top of the table and they have certainly got one of the strongest squads in the Championship.
But they are also vulnerable to one thing – pace down the flanks.
I was at their game against Coventry at St Andrews on Monday night and, while many will have been shocked to see them lose, it really could have been far worse for Birmingham.
Coventry could comfortably have triumphed by three or four.
And the key to their success was the pace, power and trickery of Jay Tabb and Michael Mifsud down the wings. They tore Birmingham to pieces at times.
And while on-loan full-back Nicky Hunt is no mug, on the other side, Franck Queudrue is definitely a weak link.
I have never rated him since his days at Middlesbrough – and he is the player Forest need to expose, by giving Paul Anderson and Garath McCleary the green light to attack from wide positions.
I know Forest have not exactly been banging in the goals lately, despite a very respectable haul of four points from two very difficult away games.
But Birmingham are there for the taking, if Forest can have the mental strength and confidence to believe it.
Yes, Birmingham are a considerable threat from set-pieces, where they have two powerful central defenders, in Liam Ridgewell and Radhi Jaidi, who are a real danger in the air.
But, as long as Calderwood keeps faith with Ian Breckin, Forest are equipped to cope.
And I can't sing the Forest's skipper's praises enough, by the way.
It is all very well having players who believe they can play their way out of trouble at the back. But sometimes you just need somebody who will head it and kick it, who will take an old-fashioned approach to defending.
Don't get me wrong, there is far more to Breckin than merely lumping the ball into row Z at every available opportunity.
He is capable of hitting a decent pass when he wants to – but he will never take a risk, never gamble on doing so.
And, more importantly, he is always talking, always cajoling and encouraging his fellow defenders.
I can't overstate how important that is.
When I came to the end of my Forest career, I was often utilised in the centre of defence. Having played as a striker for so long, I had the advantage of knowing what my opponent was thinking and where and when he was going to make his run.
But I also ended up playing alongside a young lad called Des Walker.
Now I would never claim that I taught Des how to play or that I was in any way responsible for the player he later became.
But, at the time, I would like to think that I helped him to settle into the side, to find his feet in football.
I would always help him with his positioning, guide him as to where he needed to be and who he should be watching.
And Breckin can play the same role now, in a defence that, while talented, is hardly overflowing with experience.
Overall, following their performances at Palace and Pride Park, it seems Forest are finding the winning formula.
I just hope Calderwood sticks with it.
What a fantastic turnout there was for the unveiling of the statue of Brian Clough, the man who put Nottingham, not just Forest, on the map. It cannot be underestimated the impact the man had, not only locally but also globally. You can still go abroad now and say you are from Nottingham and people mention two names – Robin Hood and Brian Clough, which says everything.
The fans who raised the money for this can be proud.

Comment on this story