What is each of MBB good at?

Bain is the clear leader in private equity DD's. Beyond that, from an industry or function perspective, there's really not a lot of difference.

Firms definitely excel at stuff, but it varies by region.

For example, BCG has basically no aerospace/defense practice in north america, but bain and mck do (and Deloitte, and strategy&). McK over indexes for government in the UK, I think.

However, this changes over time, and like Brj said, there aren't really global stereotypes for each firm regarding industry/functional expertise. A partner or three going from one firm to another can quickly change the landscape when you look at industry + regional expertise.

To answer the specific questions you asked: no idea on FS. I think McK does a bit more metals and mining than the other firms.

Thanks, I really appreciate the answers

I also want to point out that the version of "reality" that exists in each firm is different. With a handful of exceptions (e.g., Bain's famous PE work), people inside each of the firms seem to honestly think that they excel in each space, which makes it really hard to get a clear answer on questions like this; there really isn't objective data that is available to recruits.

And this doesn't just go for industry mix. I had a specific non-US geographic focus in my search and had each of the three firms tell me that they were unequivocally the largest in that geography (two more earnestly than the other). The COO of one of the firms even called me with data on headcount and billings for that geo. All three couldn't simultaneously be right, but they certainly seemed to think that they were. Plus, this business is so variable and there are many ways to cut the data (e.g., who is the biggest in the past 1 year? 5 years? By "strategy" work alone? Etc.), that you can't really get to one answer. (and yes, "biggest" is a poor proxy for "best")

If you have a specific interest, the best way to go is look for a match with partners at the geo/industry nexus that interests you. This won't answer "best," but it will confirm that the work exists. After you're in, it is just a matter of being proactive with staffing.

Perspective matters quite a bit. Even if Bain had the largest energy practice (no idea what the real stats are), if you're working in their San Francisco office, it's not going to matter much because that work is in Houston and Dallas.

You can't work on all the projects. Find the people in your office of interest that work on the thing you're interested in, and see if you click with them. By the time you're important enough for it to matter whether McK or BCG has more healthcare projects, you'll be the one selling the work.

Check out the vault rankings for best by industry.

The thing is, McKinsey is so much larger than the other two (~2X BCG + Bain) that they're going to have more experts, clients, and expertise in most sectors just by the nature of being larger.