McKinsey SolveGame 2Systems thinking
Sea Wolf comes down to one rule
Three ocean sites. Three microbes for each. A site checks the average of your three, not each microbe alone. Learn that rule here, free, and every site becomes a sum you can do in your head.
Miss it and you throw away microbes that would have passed, then run out of clock on site 3.
Pick your invitation length and test date. We email one task a day until then. Free.
- Sites
- 3
- Microbes per site
- 3
- Clock
- 30min
contaminated ocean sites, one after another
chosen from a pool of about ten
for all three sites; CaseBasix says 35
All three reported by candidates and prep sites · checked 23 Sep 2026
Free, on this page
The averaging rule, on a bench
Range × 3 = sum window
If a site wants an attribute between 4 and 6, your three microbes' values must add up to between 12 and 18. Adding three whole numbers is faster and safer than averaging them, and prep sites that rebuild the game report the bounds are inclusive.
Move the sliders. Watch for the case most people miss: a microbe that fails on its own but passes in the trio.
- Sum
- 8 + 3 + 5 = 16
- Average
- 5.33
- Sum window
- 4×3 to 6×3 = 12–18
- Verdict
- In range
Microbe 1 and 2 are out of range alone, and the trio still passes. The site checks the average, not each microbe.
Invented site briefs on a 1–10 scale, for the arithmetic only. Not taken from the game.
At every site
Three filters, in this order
Prep guides report each failed check costs 20% of a site's effectiveness. Check the cheapest things first.
Strike every microbe with an undesired trait
It breaks a check whatever its numbers are, so dropping it first costs you nothing.
Anchor one microbe with a desired trait
Prep sites read the brief as: at least one desired trait, no undesired ones. Check the brief in the game each time.
Fill the tightest sum window first
Turn each range into a sum window, start with the narrowest, and let a high microbe and a low one cancel out.
The order is our practice advice, built on the rules prep sites report. McKinsey publishes no method.
The clock
One 30-minute clock, three sites
Candidates report a single timer across all three sites. A practical target is about 9 minutes a site with 3 in hand. When a site stalls, take the 80% trio and move on: a blank site 3 costs more than an imperfect site 2.
Site 1~9 minSite 2~9 minSite 3~9 minBuffer3
A practice split, not a McKinsey rule. See every game's clock for your invitation →
McKinsey's Solve FAQ, August 2025
Solvers are sold online. Using one can cost you the offer.
McKinsey bans “applications, websites, AI tools, or pre-prepared notes” during Solve and lists the consequences: exclusion from consideration, a rescinded offer, restrictions on future applications, or legal action. It also says it may ask you to explain your logic. Practice beforehand. Take the test with your head.
Practice on DrillCase
Unlimited runs, each one checked
The walkthrough is DrillCase's Sea Wolf practice, not McKinsey footage: characteristics, sorting, the prospect pool and the final three-microbe treatment. Every run is generated from a code you can replay or send to a friend, and every run is checked before you see it: skip the preference stage and each site has a 100% answer. Set preferences, and the deal may not allow one.
- Solve Basic $99 · unlimited runs, 1 year access
- Solve VIP $159 · unlimited runs and every other game, lifetime, 7-day money-back guarantee
Questions
Sea Wolf FAQ
Sea Wolf, also called the Ocean Cleanup game, is one of the McKinsey Solve games. Candidates report three contaminated ocean sites. At each one you build a pool of microbes and submit three whose combined attributes match the site's target ranges, with trait conditions on top.
StrategyCase, MConsultingPrep and psgsecrets report 30 minutes for all three sites, and CaseBasix says 35. The 30-minute figure matches the 65-minute invitation (Redrock plus Sea Wolf). Your on-screen timer is what counts, and the tutorial before it is untimed.
Prep sites that rebuild the game report that a site checks the average of your three microbes for each attribute, not each microbe alone, with inclusive bounds. Multiply both ends of the range by three and compare the sum: an average of 4 to 6 means the three values must total 12 to 18.
It happens. Prep guides report each missed check costs 20% effectiveness, and MConsultingPrep's reconstruction notes you can settle for an 80% treatment. Keep both trait checks, miss one range by the smallest margin, submit, and protect your time for the next site.
Not during the test. McKinsey's Solve FAQ bans applications, websites, AI tools and pre-prepared notes, with consequences up to exclusion from consideration. Learn the rule well enough to do it in your head, which is what the bench on this page is for.
The averaging bench on this page is free. On DrillCase, Sea Wolf is unlimited generated runs: each run has a code you can replay or share, and each is checked before you play it so that, if you skip the preference stage, every site has a 100% answer. Runs open with Solve Basic ($99, 1 year) or Solve VIP ($159, lifetime, 7-day money-back guarantee).
No. DrillCase is independent and not affiliated with, endorsed by or sponsored by McKinsey & Company. Its Sea Wolf runs are practice built to the format candidates report.