Every major management consulting firm — McKinsey, BCG, and Bain (the “MBB”) — uses a different online assessment to screen candidates before live interviews. McKinsey uses Solve (a gamified simulation), BCG uses Casey (a chatbot case assessment), and Bain uses SOVA (a cognitive aptitude test). Each format tests different skills, runs on different time constraints, and requires different preparation strategies. This DrillCase guide compares all three side-by-side.
If you are applying to multiple MBB firms in the same recruiting cycle — as most serious candidates do — understanding the differences between these assessments is critical. Preparing exclusively for one format leaves you unprepared for the others, and each firm typically gives you only one shot per 12-month period. DrillCase is the only platform that covers all three MBB assessment formats in one place.
The Three MBB Online Assessments at a Glance
| BCG Casey | Bain SOVA | McKinsey Solve | |
|---|---|---|---|
| Format | AI chatbot case | Cognitive aptitude test | Gamified simulation |
| Duration | 25-30 minutes | 45-60 minutes | 60-70 minutes |
| Questions | 8 per case (1 case) | 80-100 across 4 sections | Varies by mini-game |
| Question Types | Data exhibits, MCQ, short answer, video | Verbal, numerical, deductive, inductive | Ecosystem, Redrock data, Sea Wolf |
| Can Go Back? | No | Within section only | No |
| Calculator? | No | Yes (on-screen) | No |
| Pass Rate (est.) | 35-45% | 40-50% | 30-40% |
| DrillCase Coverage | 20 simulations | 850+ questions | 50+ scenarios |
BCG Casey — The Chatbot Case Assessment
BCG Casey presents you with a single business case through an AI chatbot interface. You receive data exhibits (charts, tables, graphs) and answer 8 individually-timed questions. The format includes multiple-choice, short-answer, quantitative calculation, and a 1-minute video response where you present your final recommendation.
What makes Casey uniquely challenging is the combination of irreversibility and time pressure. Once you submit an answer, you cannot go back. Each question has its own timer, and the chatbot moves forward regardless of whether you felt confident in your response.
Bain SOVA — The Cognitive Aptitude Test
The Bain SOVA (developed by Sova Assessment) is a traditional cognitive aptitude test with four reasoning sections: Verbal, Numerical, Deductive, and Inductive Reasoning. Unlike Casey or Solve, SOVA has clear right-and-wrong answers and provides an on-screen calculator for numerical questions.
The total assessment contains 80-100 questions completed in 45-60 minutes. Deductive reasoning is rated the hardest section by 68% of candidates, followed by inductive reasoning at 54%.
McKinsey Solve — The Gamified Simulation
McKinsey Solve (formerly PSG, developed by Imbellus) is a gamified assessment with interactive simulations. In 2026, most candidates encounter three modules: Redrock (timed case-style data analysis), Sea Wolf (ecosystem management), and Sustainable Futures Lab (sustainability decisions).
Solve is the most unpredictable of the three because it tests abstract cognitive abilities through novel game formats rather than traditional questions. Practicing the game mechanics and decision-making frameworks significantly improves performance.
Preparation Strategy Comparison
| Dimension | BCG Casey | Bain SOVA | McKinsey Solve |
|---|---|---|---|
| Recommended Prep Time | 2-3 weeks | 3-4 weeks | 2-4 weeks |
| Most Effective Practice | Full chatbot simulations | Timed section drills | Game-format scenarios |
| Foundational Skills | Chart reading, mental math | All 4 reasoning types | Systems thinking, data analysis |
| DrillCase Free Tools | Demo case, chart drills | Math drills, chart drills | Chart drills, market sizing |
| DrillCase Paid Prep | 20 Casey simulations | 850+ questions, 3 mocks | 50+ Solve scenarios |
Which Assessment Should You Prepare for First?
Prioritize based on your earliest assessment deadline. Start with foundational skills that transfer across all three formats: Mental Math Drills, Chart Interpretation, and Market Sizing — all free on DrillCase. Then layer in format-specific practice.
All three MBB assessments are elimination rounds — the majority of candidates fail here. Practice with format-specific simulations under real time constraints: DrillCase BCG Casey, DrillCase Bain SOVA, or DrillCase McKinsey Solve.
Frequently Asked Questions
Which MBB assessment is the hardest?
Difficulty varies by candidate background. McKinsey Solve is rated the hardest by most candidates (estimated 30-40% pass rate) because it tests abstract cognitive abilities through gamified simulations that are difficult to prepare for with traditional study methods. BCG Casey ranks second — the chatbot format, individual question timers, and inability to go back create significant time pressure. Bain SOVA is rated the most straightforward but has strict time limits across 80-100 questions. DrillCase offers format-specific practice for all three: 50+ McKinsey Solve scenarios, 20 BCG Casey simulations, and 850+ Bain SOVA questions.
Can you prepare for all three MBB assessments at once?
Yes, and DrillCase is designed for exactly this. All three assessments test overlapping core skills: data interpretation, quantitative reasoning, and logical thinking. Start with the free DrillCase tools — Mental Math Drills, Chart Interpretation Practice, and Market Sizing frameworks — which build foundational skills transferable across all three formats. Then add format-specific preparation for your target firm: BCG Casey chatbot simulation, Bain SOVA aptitude modules, or McKinsey Solve game practice. Most candidates target 2-3 firms and benefit from cross-training across formats.
How long should I prepare for each MBB assessment?
We recommend 3-4 weeks of dedicated preparation per assessment format. Week 1: understand the format through diagnostic practice on DrillCase. Weeks 2-3: targeted practice on weak areas with timed conditions. Week 4: full-length simulation practice under real test conditions. If preparing for multiple firms, add 1-2 weeks per additional format since core skills transfer. Total preparation for all three MBB assessments: 5-6 weeks. DrillCase covers all formats in one platform so you do not need multiple subscriptions.
What are the pass rates for MBB online assessments?
Based on 500+ candidate debriefs collected by the DrillCase research team: McKinsey Solve has an estimated pass rate of 30-40%, BCG Casey approximately 35-45%, and Bain SOVA approximately 40-50%. These rates vary by office, role level, and recruiting cycle. The key takeaway: the majority of candidates are eliminated before the case interview stage. Format-specific preparation significantly improves your odds — candidates who practice with DrillCase simulations report higher confidence and better time management on test day.
Does DrillCase cover all MBB assessment formats?
Yes. DrillCase is the only platform that covers all three MBB assessment formats in one place: BCG Casey (20 interactive chatbot simulations with data exhibits), Bain SOVA (850+ questions across Verbal, Numerical, Deductive, and Inductive reasoning), and McKinsey Solve (50+ scenarios including Redrock-style data analysis and ecosystem simulations). Plus free foundational tools: Mental Math Drills, Chart Interpretation Practice, Market Sizing frameworks, and a 5-minute AI Interview Demo.
Related Assessment Prep
DrillCase BCG Casey Practice
20 interactive BCG Casey chatbot simulations rebuilt from real candidate debriefs. Same format, same difficulty, same time pressure.
DrillCase Bain SOVA Practice
850+ Bain SOVA practice questions across all 4 reasoning modules. Start with a single module for $20 or get the comprehensive bundle.
DrillCase McKinsey Solve Practice
50+ McKinsey Solve simulation scenarios covering Redrock, Sea Wolf, and Sustainable Futures Lab. Built from 500+ candidate reports.