Hey guys, some people seem to benefit from a guide I wrote on how exactly I got 10th decile in McKinsey Solve, so posting it here.

Hope it helps!

TL;DR

• McKinsey Solve = difficult because of time pressure, not maths
• 3 games:
  • Red Rock: simple math + info overload >>> filter relevant info and don’t overcomplicate
  • Sea Wolf: logic + speed >>> basic rules to follow for microbe selection and do it quick
  • Sustainable Futures Lab (new): judgment test for balance trade-offs >>> think like a consultant: what hurts the business most?
• Common mistakes: overthinking, wasting time, ignoring basics, getting lost in info
• What works:
  • identify what’s actually being asked
  • use only relevant data
  • quick sanity checks
  • optimize for speed + clarity
• Prep: 1–2 practice runs per game is enough if you review mistakes

Bottom line: it’s not hard—people fail because they try to figure it out during the test instead of beforehand.

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How I got a 10th decile score

Mckinsey Solve Overview

There are currently three games:

1. Red Rock Study (35 minutes): An interactive case with exhibits, calculations, and a written/visual report component, plus independent math questions
2. Sea Wolf (30 minutes): A logic and optimisation game where you're building microbe-based treatments across three sites, managing trade-offs between attributes and traits
3. Sustainable Futures Lab (NEW as of April 2026, 20 minutes): A consulting-style situational judgment test with 13 questions that ask you to balance competing priorities—think speed vs. quality, cost vs. impact

Test is hard because of time pressure and trying to understand ambiguous questions/info. There is no hard maths (but you should be quick with the basics).

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Red Rock

Mistakes to avoid:

- Re-reading: You reread the question, look over the exhibit again, doubt your answer because your not even sure what this weirdly phrased question is asking, recalculate, and suddenly 3.5 minutes are gone on a single question.

- Overcomplicating the maths: Following from the last point, you think that the question couldn't be asking you the obvious thing because it would be too simple for McKinsey, so you chose to do the hard thing. All the maths is simple.

- Not checking for mistakes: you're under time pressure you don't stop to sense check your answers.

- Getting lost in data: You are given tons of data (particularly in Redrock), and you're treating all of it as equally important.

Here's how to tackle these issues:

1. Identify what's being asked This is tricky to describe because you won't understand what I mean when I describe the questions as confusing until you get to the test. Try the free Redrock case at solvegamesguide.com – it mimics it almost precisely. Casebasix.com also has a decent one.
2. Locate the relevant data They will throw a lot of numbers and info at you that are irrelevant. It can easily make you doubt whether your simple approach is the correct one. Don't let it trick you. Only look at numbers you are asked about.
3. 10-second sanity check Does the magnitude make sense? Are the units right? Is the direction correct?

Regarding math skills: Percentage changes, weighted averages, ratios, and chart reading. Speed and accuracy on the basics is all you need.

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Sea Wolf

Sea Wolf Overview:

- Phase 1 (Profiling): >30 seconds. Choose the desired trait and also the attribute that has the biggest outlier target range. This is testing reasoning, not affecting gameplay. Decide quickly and move on.

- Phase 2 (Categorization): Speed-focused: sort microbes fast. Be careful not to make mistakes, especially in site 2 and 3 where you might accidentally categorize according to what you were doing from the previous site (happened to me before I caught myself).

- Phase 3 (Prospecting): You're selecting microbes for your pool of 10. This is where you need to be quick with the basic maths to kind of see which microbes you should pick - you don't have to be precise here because you'll waste too much time.

- Phase 4 (Treatment): Your treatment score should be 100% on 2 or 3 sites and possibly 1 site with 80%. Fastest way to calculate microbes is to just triple the target ranges and sum your microbe selections to see if they fall in range.

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Sustainable Futures Lab

What is it: McKinsey introduced Sustainable Futures Lab to the Solve as of April 2026 as a situational judgement element.

You're given a mission briefing on an ecological project, then you answer 13 questions (1 ranking, 12 multiple choice) in 20 minutes. You will have to make trade-offs: speed vs. quality? Cost vs. environmental impact? They're clearly testing how you think about stakeholder priorities and constraints.

The good news: if you have real consulting experience this will seem intuitive (at least, for me) as the game is quite realistic. I haven't seen much on this test because its new but I used solvegameguide's multiple free scenarios of the game.

Approach: If I was to describe my own thinking that I used to get a 10th decile score, I would say: *as a consultant, you are ultimately part of a business that delivers a service. When balancing priorities you want to filter everything through that lens*

- Failing to deliver = harming business

- Harming client relationships = harming business

- Poor decision qualities = harming business

- Harming team morale = harming productivity = harming business

This makes it easier to understand what tradeoffs to make. E.g. if faced with deciding whether to fail delivering an outcome VS harming team morale, clearly failing to deliver would have a bigger impact on business.

Everything boils down to business. Working at McKinsey (or any company) is not about making friends lol.

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Practical Prep Strategy

You don't need to overdo this. The test is not demanding once you've familiarised yourself with it.

If you use the free simulators you'll get the practice you need; you'll see the maths is nothing crazy and it's just a matter of alleviating time pressure by familiarising yourself.

Free Simulators:

1. solvegamesguide.com – one Redrock case (most accurate case), one Sea Wolf trial site, 3 Sustainable Futures Lab scenarios
2. mconsultingprep.com – one Redrock case
3. casebasix.com – one Redrock case, (they previously had a partial sea wolf but I couldn't find it after they updated their resources, but at least Redrock looks better)

I'm also curious if any one has taken the Sustainable Futures Lab test? I thought it was honestly very close to my management consulting experience, but wonder how other felt.