BCG structuring depth vs McKinsey

Hi there! 

Well... the truth is quite ugly.

Most interview prep resources are not just imperfect.
They are actively misleading.

The entire “BCG case vs McKinsey case” narrative is a symptom of that.

People talk about “BCG style” and “McKinsey style” because they are studying artifacts, not reality.

Those so called “BCG cases” you see online are usually one of two things.
Polished marketing exercises created by recruiting teams for their firms' career pages.
Or worse, memory reconstructions written by candidates after the interview.

Candidates who were stressed.
Candidates who only remember fragments.
Candidates who mostly didn't even pass!

Then they go home, fill in the gaps, invent a rationale, and publish a “model solution” for their consulting club's PDF collection of "Real MBB Cases".

And the prep industry builds doctrine on top of that.

This is how you end up with absurd debates about how many levels deep your tree should be.
As if partners sit there with a checklist saying “Level three good, level four too much”.

They do not.

Real interviews are not scripted.
Real cases do not have canonical solution paths.
And real interviewers are not grading trees.

They are watching something much more basic and much harder to fake.

Do you understand what matters right now.
Can you choose a sensible direction without hiding behind completeness.
Can you change altitude when the situation changes.

That is it.

Everything else candidates obsess over is just theater.

And once you see this, it is very uncomfortable.
Because it means much of what you studied was noise.
It also means the reason you feel confused is not you.

It is the resources you consume and treat like gospel.

People who have actually sat on the interviewer side for McKinsey and BCG know this.
People who have not keep debating “styles”.

That moment, when this clicks... that is the real turning point.

Cheers, Sidi

____________________

Dr. Sidi S. Koné

The difference trips up a lot of people who switch between McKinsey and BCG prep.

Here's how I'd think about it.

In McKinsey interviews, the structure is often the main event. You lay out a detailed issue tree, interviewer reacts, then guides you through it. Going to level 3-4 can work because you're showing your thinking upfront and the interviewer takes control after.

BCG is different. You're driving the case. If you spend five minutes presenting a deep issue tree at the start, you've used up time you need for analysis. And frankly, you'll bore them. They want to see you move.

For BCG, present two layers max when you structure. Your main buckets and one level underneath. Keep it to 60-90 seconds. Then state which bucket you want to start with and why. That's where you show depth, through the analysis, not the upfront structure.

Think of it this way. McKinsey evaluates your structure as a deliverable. BCG evaluates your structure as a starting point. At BCG, depth shows up through how you prioritize, what questions you ask, how you dig into each area, and how you adjust as you get data.

A few practical tips:

Keep your initial structure simple and decision-oriented. Three to four buckets, each clearly linked to answering the main question.

Don't present sub-sub-branches upfront. Mention them when you actually go into that area.

After laying out the structure, explicitly prioritize. Say something like "I'd start with X because it's most likely to drive the answer."

Then go deep on that bucket. That's where you show your thinking. Ask for data, interpret it, draw conclusions, then decide whether to move to the next area or dig deeper.

BCG cares less about how pretty your initial tree looks and more about how you navigate the problem in real time.

This is one of the most common pitfalls for candidates transitioning between the two firms' styles. You’re right to notice the difference, and it’s less about the visual output and more about the underlying philosophy of the candidate-led interview.

Here is the key distinction: McKinsey interviews often test your ability to build a comprehensive, air-tight safety net—a structure that covers every base (hence the L3/L4 detail upfront, ensuring MECE is proven). BCG is testing your ability to rapidly prioritize and own the ambiguity.

For a BCG candidate-led case, you absolutely should not present L3 or L4 detail in the initial verbal structure. That depth will be viewed as rigid and a poor use of time. Your initial presentation should be high-level—Level 1 buckets, perhaps one key Level 2 split if it’s critical to your prioritization hypothesis—and that's it. You must demonstrate that your structure is a living hypothesis, not a completed blueprint.

BCG evaluates depth not at the structuring moment, but through the subsequent analysis and prioritization. The interviewer wants to hear the top-level branches, and then immediately hear your logic for why you are prioritizing Branch A over Branch B. Your deeper rigor (the L3/L4 knowledge you built in your McK prep) should be evident when you dive into that single prioritized branch, defining the necessary data, or explaining the calculations required to prove or disprove your hypothesis. If you spend 5 minutes outlining L4 structure, you have lost control of the clock and demonstrated a lack of commercial judgment about where the highest impact lies.

Focus on setting up a clear, decision-oriented structure, pivot quickly to your hypothesis, and then let your depth shine when you are challenged on the specifics of the prioritized area.

All the best!

Hey there, 

I wouldn’t think about this as depth vs. no depth between McKinsey and BCG. In both firms, you typically have ~2 minutes to structure, and that time should be used to build a solid L1 and L2 structure that is clearly MECE and case-specific.

A structure that is too high-level is usually not sufficient at either firm and it often stays generic and doesn’t give you enough traction to actually solve the case.

What I do see as a nuance in BCG candidate-led cases is slightly more emphasis on being very explicit about what the case is trying to solve for (the decision or hypothesis you make), and then anchoring the structure around that/diving deeper into that. But it still needs to be complete and rigorous.

A practical way to handle this in the 2-minute window:

• Build strong and MECE L1 and L2 quickly (this is non-negotiable at both firms)
• If time allows, definitely go deeper (L3, sometimes L4) in the bucket you believe will matter most
• Use that deeper branch as your anchor for where you expect the case to go and where you’d start the analysis

This shows two things interviewers care about:

1. you can structure the full problem properly, and
2. you can prioritize and signal depth where it matters most.

So the difference isn’t that BCG wants “shallow” structures, it’s that they value intentional depth: going deep in the right place, rather than everywhere by default

That mindset works well for both BCG and McKinsey in practice.

Hope this helps!

Honestly, people are making a much bigger deal out of this than it really is. 

I've coached around 400 people by now, and ~70% of the offer holders went to MBBs. The approach that I've used in coaching them has been virtually the same. 

In fact, I recommend people to assume all cases are candidate-led, because if you signal that you know how to lead the case, that's going to be incredibly valuable even in a McKinsey interviewer-led case. 

All consulting firms look for virtually the same things. Any claim that suggests they look for something different is partly an effort at marketing difference rather than actual difference in substance. 

In short, don't worry about switching from one to the other. Make sure that you are effective at doing the cases. A candidate that delivers an excellent case performance at McKinsey, will never provide a bad case experience at BCG because of some assumptions that they should go X levels deep instead of Y levels deep. 

Best,
Cristian

hey there :)

great question and you are observing this correctly. in BCG candidate led cases the expectation is a clear high level decision oriented structure at the start, usually level one to two, and then showing depth through smart prioritization and sharp analysis as you go. laying out very deep trees upfront often feels too theoretical for BCG and can slow you down, whereas McKinsey tolerates more upfront depth. BCG mainly evaluates depth through how you navigate the case, not how complex the initial structure sounds. let me know if you want to prep together, I got the cross offer and know exactly what to look for.

best,
Alessa :)

Hi there,

Yes this is a key difference between the two interview styles. For BCG, one should present up to Level 2 and Level 3 only for some branches that they consider a priority, and then drive the interview by asking for information required.

This is a common question on the differences between BCG / McKinsey style of interviews etc.

If you believe that there is a fundamental difference in what problem solving and logic is between the MBB firms... then sure there might be a difference.

But a hypothesis is a hypothesis, logic is logic, the Pyramid Principle doesn't change just because the firm name is different. 

Like others have mentioned, I think you are worrying about the wrong things here.