Short answer
McKinsey, BCG and Bain each screen candidates with a different online test. McKinsey Solve is two or three ecology games, reported at 65 or 85 minutes. BCG Casey is a chatbot case of about 30 minutes plus a short video. Bain uses Sova or TestGorilla, about 30 to 40 minutes. Each tests different skills.
Key takeaways
- The three tests differ in format, length, calculator rules and whether you can go back.
- Core skills such as chart reading and mental math transfer across all three; the formats do not.
- Prepare first for the firm with the earliest deadline, then add the other formats.
In this article
Part ofConsulting Online Assessments: Which Test Will McKinsey, BCG or Bain Send You?
McKinsey, BCG and Bain (the "MBB" firms) each use a different online test to screen applicants before live interviews. McKinsey sends Solve, a set of ecology-themed games. BCG usually sends Casey, a chatbot-led business case. Bain sends a Sova or TestGorilla reasoning test. This page compares the three side by side; the MBB online assessments guide goes deeper on each.
The three tests at a glance
| McKinsey Solve | BCG Casey | Bain (Sova or TestGorilla) | |
|---|---|---|---|
| Format | Two or three ecology games | Chatbot-led business case, then a video | Multiple-choice reasoning and judgement |
| Length | Set by the invitation; reported 65, 85 or 95 minutes | About 30 minutes (BCG), plus the video | About 30 to 40 minutes (Bain) |
| Questions | Varies by game | About 8 to 10, starting with dataset selection (reported) | Varies by platform and section |
| Going back | Varies by game | No (reported) | TestGorilla: no. Sova: no per-question countdown |
| Calculator | No outside calculator (McKinsey); Redrock reportedly has one on screen | Reportedly allowed | Allowed, with pen and paper (Bain) |
| Business knowledge | Not needed (McKinsey) | Case skills help | Not needed |
McKinsey Solve
Solve is the game-based test McKinsey sends to most applicants. Candidates currently report two core games, Redrock (a research-and-calculation study) and Sea Wolf (choosing microbes that meet a set of conditions), with the Sustainable Futures Lab added in longer invitations. McKinsey says no business knowledge is needed, and its rules forbid apps, websites, AI tools, prepared notes and outside calculators. Full detail: McKinsey Solve guide.
BCG Casey
Casey is a chatbot that runs one business case. BCG says it takes about 30 minutes. Candidates report 8 to 10 questions answered one at a time with no going back, starting with a dataset-selection question and ending with a 60-second video recommendation. Some BCG processes add or substitute the SHL-based CCA; see Casey vs CCA. Full detail: BCG online case guide.
Bain: Sova or TestGorilla
Bain's test runs on one of two platforms, and your invitation says which. Bain gives about 30 to 40 minutes and allows pen, paper and a calculator. Sova mixes numerical, verbal and logical reasoning with situational judgement and a personality questionnaire, with no per-question countdown. TestGorilla is a set of separately hard-timed tests with no going back. Full detail: Bain online test guide.
How preparation differs
| McKinsey Solve | BCG Casey | Bain | |
|---|---|---|---|
| Most useful practice | Game-format scenarios under the clock | Timed chat-format cases with exhibits | Timed section sets |
| Core skills | Data reading, ratios, systematic elimination | Structuring, math, chart reading, a clear recommendation | Percentages, verbal logic, deductive puzzles |
| Free starting point | Solve-style demo scenario | Casey-style demo case | Bain-style verbal sample |
| DrillCase practice | 20+ Solve-style scenarios | 25+ Casey-style cases | 450+ questions, 3 mock tests |
Which should you prepare for first?
Start with the skills all three share, using the free math, chart and market-sizing drills. Then prepare for the test with the earliest deadline, because its invitation arrives first. The assessment timeline shows how little time there is between application and test.
Frequently asked questions
Which MBB assessment is the hardest?
It depends on your background, and no firm publishes difficulty or pass-rate data. Candidates with little gaming experience often find Solve the least familiar, because it is a set of games rather than questions. Casey adds a clock and a no-going-back rule to a business case. The Bain test is the most conventional, but TestGorilla sections are tightly timed. Try a sample of each before deciding where to spend time.
Can you prepare for all three MBB assessments at once?
Partly. Percentage math, chart reading and timed decision-making carry across all three, so build those first; DrillCase's math, chart and market-sizing drills are free. The formats themselves do not transfer: Solve is a set of games, Casey is a chat-based case with a video answer and Bain's test is multiple choice. Add format practice in the order of your deadlines.
How long should I prepare for each MBB assessment?
Two to three weeks per format is a common plan when you start from scratch: a few days to learn the format, then timed practice on weak areas, then one or two full-length runs. Core skills carry over, so a second or third format usually needs less time. If an invitation arrives with only a few days to spare, prioritise format familiarity.
What are the pass rates for MBB online assessments?
Firms do not publish pass rates, and the third-party estimates in circulation are not based on disclosed data, so we do not quote one. What candidates consistently report is that many applicants are screened out at this stage, which is why format-specific preparation matters.
Does DrillCase cover all MBB assessment formats?
Yes, with practice material rather than the firms' own tests: 25+ BCG Casey-style chatbot cases, 20+ McKinsey Solve-style scenarios (Redrock, Sea Wolf and Sustainable Futures Lab formats, plus an Ecosystem archive) and 450+ Bain-style aptitude questions across 23 timed sets, plus 3 full mock tests. The math, chart and market-sizing drills and a 63-case library are free.
FreePick your test
Your invitation already names your test. Prepare for that one.
McKinsey, BCG and Bain each screen with a different test on a different clock. Practice for the wrong format and test day is the first time you see the real one. Open the free check for yours: it reads what your invitation says, then sends a plan to your date if you want one.
- If it saysMcKinsey SolveYour invitation's length tells you which games you'll play and on what clock.Decode my Solve invite
- If it saysBCG CaseyCasey or the CCA: see which test BCG named and how its clock runs.Decode my BCG invite
- If it saysBain online testSova or TestGorilla: the clock, the sittings, and whether you can go back.Check my Bain platform
Practice what you just read
Applying to more than one firm? Practice all three formats
Each firm tests something different, so each needs its own practice. DrillCase has a simulator per format and a free case library for the skills they share.
- simulations across 3 firms
- 75
- practice questions
- 1,333
- free library cases
- 63
- 29 BCG Casey-style cases, 21 McKinsey Solve-style scenarios, 476 Bain-style questions
- 63 free library cases and 582 drill questions (math, charts, market sizing)
- The All-Access Pass unlocks every firm product for one payment; the top tier of each bought separately comes to $457
The All-Access Pass ($250) carries a 7-day money-back guarantee. Refund policy. DrillCase is independent practice material and is not affiliated with McKinsey, BCG or Bain.
Sources
- McKinsey & Company: Interviewing at McKinsey (Solve section)
- McKinsey & Company: Assessment integrity expectations
- BCG Careers, Mexico: Online Case Experience (OCE) and CCA
- Bain & Company: Digital assessment (hiring process)
- StrategyCase: McKinsey Solve guide
- Hacking the Case Interview: BCG online case (chatbot) interview
- Hacking the Case Interview: Bain TestGorilla assessment