Tasks / Challenge

Challenge an idea

Can the model find the strongest reason an idea may fail, backed by evidence?

Measures the systemTask v1.2 · 2 casesDifficulty

What AI gets right here, and what you’ll still have to catch

From 14 graded outputs by 7 models. 64% were usable with at most a quick edit.

Reliably right

  1. Addresses the actual decision100% pass
    It commits early to not committing three squads and authorizing a six-week test, and specifies what result would change that.
    GPT-6.1 Sol · API · The CEO's embedded-payments bet
  2. Identifies material uncertainty100% pass
    It names the unknowns (representativeness of payment data, large-account volume access, actual mix) and resolves them with a bounded test.
    GPT-6.1 Sol · API · The CEO's embedded-payments bet
  3. Uses the interviews faithfully100% pass
    All quotes are accurate and correctly attributed to A05, A08, A04, A07, and A12.
    GPT-6 Luna · API · An AI SDR for small agencies

Where it slips

  1. A cheap test that can actually read out64% pass
    The pre-registered gate requires signed deals and renewal rather than an early signal such as qualified meetings or proposals, so it risks being too late for a cheap read-out.
    GPT-6.1 Sol · API · An AI SDR for small agencies
  2. Re-estimates the revenue correctly71% pass
    It shows working but lands on a central $2.3M and $1M–$6M range, not roughly the $5–10M range required by the grading rubric, and its $9.1M pilot upper bound is not used as the main re-estimate.
    Sonnet 5.5 · API · The CEO's embedded-payments bet
  3. Avoids unsupported claims71% pass
    The memo claims the pilot achieved ~0.38% blended take as a fact, which is not in the evidence and is not derived from it arithmetically; it also treats the pro-rata $1.43B locked value as a hard constraint without flagging the assumption.
    Opus 5.5 · Claude · The CEO's embedded-payments bet

Case viewer

Read the brief, then put up to three outputs side by side, each with the LLM judge’s verdict on every check. Highlights mark what a PM had to fix.

The brief

You're a Staff PM at Fieldline. Our CEO wants to commit three squads for three quarters to Fieldline Pay, embedded payments for our customers' invoices, and has told the board it could add $24M of annual revenue within two years. Priya Raman, our CPO, has asked you to write the strongest challenge to the plan as a pre-read for next week's exec offsite. The CEO, CFO and Head of Sales will all read it. Write a memo of no more than 1,200 words that: 1. Names the single assumption the plan most depends on that the evidence does not support, and shows why, using the numbers in the pack. 2. Re-estimates the revenue from the supplied data, showing your working, as a range. 3. Says what we would need to see to be proved wrong, and the cheapest test that would show it within six weeks. 4. Says what, if anything, we should do instead or how the bet should change. The pack below is everything we have. Some of it matters more than the rest.

What the model was given11 items: About Fieldline, CEO's memo to the exec team (excerpt), CFO's revenue model, Invoicing data (last 12 months, all customers), How invoices are paid today, Payments partner term sheet (unit economics), Pilot (4 months), Sales notes on the largest accounts, Customer interviews (22 customers, last quarter), Competitor, Engineering
About FieldlineField-service software for trades businesses (plumbing, HVAC, electrical): scheduling, dispatch, quotes and invoicing. 2,300 customers, $41.0M ARR, average $17,800 per customer. Series C; the next raise is planned in about 14 months.
CEO's memo to the exec team (excerpt)“Every invoice our customers send is money we don't touch. Our customers invoiced $4.83B last year through Fieldline. If we process those payments, we become part of how they get paid, not just how they schedule. The model is simple: 70% of customers adopt within 18 months, the average customer invoices $2.1M a year, and we keep a 0.7% blended net take. That is $24M of new annual revenue by month 24, more than half our current ARR, and it makes the next raise a very different conversation. Tradesly has shown it works: payments are now 22% of their revenue. I've told the board I believe payments can be 35% of our revenue by 2028. I want three squads on this from next quarter, which means pausing the scheduling rewrite.”
CFO's revenue modelCustomers: 2,300. Adoption by month 18: 70% (1,610 customers). Annual invoiced value per customer: $2.1M (total invoiced $4.83B ÷ 2,300). Blended net take rate: 0.7%. Month-24 revenue run-rate: 1,610 × $2.1M × 0.7% = $23.7M. CFO's note: “Adoption and take rate are the CEO's assumptions. I haven't stress-tested them.”
Invoicing data (last 12 months, all customers)Total invoiced value: $4.83B. Mean per customer: $2.1M. Median per customer: $640k. The largest 5% of customers (115) account for 48% of invoiced value ($2.32B). By job type, residential jobs are 42% of invoiced value and commercial jobs (property managers, facilities contracts) are 58%.
How invoices are paid todayFrom the 690 customers (30%) who record the payment method in Fieldline, by share of invoice value: card 19%, ACH/bank transfer 44%, check 31%, cash 6%. Card share is 38% of residential invoice value and 5% of commercial. Average commercial invoice: $3,800; average residential invoice: $410. Commercial clients pay on net-45 or net-60 terms; the average commercial invoice is paid 52 days after it is sent.
Payments partner term sheet (unit economics)Card: the customer is charged 2.9% + $0.30 per payment; our all-in cost (interchange, network, partner fee) is about 2.2%, so we net about 0.7% of card value. ACH: the customer is charged a flat $2.00 per payment; our cost is $0.40. Checks and cash earn nothing unless the payer switches to card or ACH. The partner handles licensing, KYC and risk; they have approved our application.
Pilot (4 months)62 customers invited, 38 adopted (61%). Pilot customers' invoice value is 64% residential (the customer base is 42%). With pay-by-link on every invoice, card share of invoices paid through Fieldline Pay rose to 71% for residential and 6% for commercial. Net payments revenue, annualised: $214k across the 38 customers ($5,630 per customer per year).
Sales notes on the largest accountsOf the 115 largest customers, 71 have multi-year contracts with an existing payment processor, most running to 2028. Head of Sales, in Slack: “None of the big ones will move processors before their contracts end, and their property-manager clients will not pay 2.9% on a $3,800 invoice. They'll pay by ACH or check like they always have.”
Customer interviews (22 customers, last quarter)17 of 22 named getting paid on commercial jobs as their biggest cash problem (“I'm floating $200k of payroll while property managers sit on invoices for two months”). 9 said they would pay a fee to be paid faster. 6 said they won't offer card payment because clients fight the surcharge. Of the 14 customers with mostly commercial work, 11 said their clients require ACH or check.
CompetitorTradesly launched embedded payments in 2025 and says payments are now 22% of its revenue. Its published case studies are almost all home-services businesses; it describes its customers as about 80% residential.
EngineeringThe plan needs three squads for three quarters. The scheduling rewrite it would pause is the top-cited reason for churn among customers with more than 50 technicians (lost ARR from that segment last year: $1.9M).
What a strong answer doesThe answer key the graders mark against

Names the load-bearing assumption as the 0.7% blended net take: that is the card margin applied to all invoiced value, but only about 19% of value is paid by card (5% of commercial, which is 58% of value), ACH nets about 0.04% on a $3,800 invoice, and checks and cash earn nothing. Re-estimates with the supplied data: even at the pilot's improved mix (about a third of value on card), the blended take is roughly 0.2–0.25%, so the run-rate is about $5–9M, not $24M (the pilot's $5,630 per customer × 1,610 = $9.1M is an upper bound because the pilot was residential-heavy; the 71 locked-in large accounts, with 48% of value in the top 5%, cut it further). Notes that $24M needs essentially all invoice value on card. Treats Tradesly as a residential-mix result, not proof, and engineering capacity, licensing and competition as secondary. Keeps what the evidence supports: card payments work for residential invoices, and the strongest pull is commercial cash flow (17 of 22), so it reshapes the bet toward faster payout or financing on commercial invoices, which earns on the volume the processing model can't. Proposes a cheap test with a threshold that would prove the challenge wrong (for example, commercial card share well above 20% with pay-by-link in a six-week cohort, or uptake of paid instant payout), and is written for a room that includes the CEO: firm on the numbers, not personal.

Critical failures (cap the score at 40)
  • Accepts the $24M projection or the 0.7% blended net take rate as sound
  • Invents market sizes, competitor figures or customer statistics that are not in the pack
Case

Staff-level · v1.7 · synthetic · B2B SaaS, fintech, strategy, staff-level

The outputs

7 setups answered this brief. Pick up to three to read side by side.

Critical failure: Invents market sizes, competitor figures or customer statistics that are not in the pack. Score capped at 40.

Needs more than a quick edit6 of 11 checks passed

A PM would need to recheck the locked-GMV arithmetic and the revenue model assumptions before using it. The memo is also too long for the stated constraint.

Output

MEMORANDUM

TO: Exec Team (CEO, CFO, CPO, Head of Sales) FROM: Staff Product Manager DATE: October 24, 2024 SUBJECT: Strategic Challenge & Alternative Plan: Fieldline Pay

---

Executive Summary

Committing three squads for three quarters to Fieldline Pay under the current $24M revenue projection risks our 14-month Series raise.

The $24M model assumes a 0.7% blended net take rate across our total $4.83B GMV. In reality, our invoice mix (58% commercial) and payment fee structure yield an effective take rate of roughly 0.15%–0.28% on accessible volume. Realistic Month-24 payments revenue is $4.8M–$7.8M—an 68%–80% shortfall against the board commitment.

Simultaneously, pausing the scheduling rewrite directly imperils our core ARR by aggravating churn in our highest-value segment (which lost $1.9M ARR last year). We must right-size this bet, protect core retention, and re-orient our fintech strategy around commercial cash flow.

---

1. The Fatal Assumption: A 0.7% Blended Net Take Rate on Total GMV

The $24M model hinges on earning 0.7% net margin on $3.38B of adopted GMV (70% of $4.83B). The data contradicts this in three ways:

#### A. Card Economics Do Not Apply to Commercial GMV (58% of Volume) Our partner agreement gives us 0.7% on card volume (2.9% + $0.30 fee less 2.2% cost), but only a flat $1.60 net per ACH transaction ($2.00 fee less $0.40 cost), and $0 on checks/cash. * Commercial jobs represent 58% of our GMV ($2.80B) with an average invoice of $3,800. * Property managers will not pay a 2.9% card surcharge ($110.20 per invoice). In our pilot, commercial card adoption barely moved: from 5% baseline to just 6%. * Monopolized by ACH, a $3,800 commercial invoice earns us a flat $1.60. That is an effective take rate of 0.042% (4.2 basis points)—not 70 basis points.

#### B. The Tradesly Comparison is a False Equivalency Tradesly's 22% payments revenue share is driven by a customer base that is ~80% residential. Fieldline’s base is 58% commercial. Residential customers pay $410 tickets where card convenience wins (pilot card share hit 71%). Commercial clients operate on net-45/60 terms and require ACH or check (11 of 14 interviewed confirmed this). Applying residential payment dynamics to a commercial invoice base is fundamentally flawed.

#### C. 30% of Total GMV Is Contractually Inaccessible Until 2028 The largest 5% of our customers (115 accounts) control 48% of total invoiced volume ($2.32B). Sales confirmed that 71 of these 115 accounts are locked into multi-year processor contracts running to 2028. That removes ~$1.43B in GMV from near-term adoption.

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2. Revenue Re-Estimation (Month-24 Run-Rate)

#### Addressable GMV & Unit Take Rates * Total GMV: $4.83B * Less Contractually Locked Tier-1 GMV: -$1.43B (71/115 largest accounts) * Net Addressable GMV: $3.40B * Residential (42%): $1.43B (avg ticket $410 $\rightarrow$ ~3.48M invoices) * Commercial (58%): $1.97B (avg ticket $3,800 $\rightarrow$ ~518k invoices)

#### Expected Net Revenue per $1M GMV (Based on Pilot Performance): * Residential ($1M GMV): * 71% Card ($710k $\times$ 0.70%) = $4,970 * 25% ACH ($250k $\div$ $410 = 610 txns $\times$ $1.60) = $976 * 4% Check/Cash = $0 * Residential Blended Take Rate: ~0.59% * Commercial ($1M GMV): * 6% Card ($60k $\times$ 0.70%) = $420 * 60% ACH ($600k $\div$ $3,800 = 158 txns $\times$ $1.60) = $253 * 34% Check = $0 * Commercial Blended Take Rate: ~0.067% (6.7 bps) * Portfolio Blended Take Rate on Accessible GMV: $(0.42 \times 0.59\%) + (0.58 \times 0.067\%) =$ 0.287%

``` +------------------------------------+------------------+------------------+------------------+ | Metric | Conservative | Base Case | Aggressive | +------------------------------------+------------------+------------------+------------------+ | Accessible GMV Adoption | 40% ($1.36B) | 55% ($1.87B) | 70% ($2.38B) | | Res / Comm Effective Take Rate | 0.22% (Card dips)| 0.28% (Pilot mix)| 0.33% (Card lift)| +------------------------------------+------------------+------------------+------------------+ | Re-estimated Month-24 Revenue | $3.0M | $5.2M | $7.8M | +------------------------------------+------------------+------------------+------------------+ | Shortfall vs. $24M Plan | -$21.0M (-87%) | -$18.8M (-78%) | -$16.2M (-68%) | +------------------------------------+------------------+------------------+------------------+ ``` (Sanity check against pilot: 38 pilot customers generated $214k/yr = $5,630/customer. If 1,610 customers adopted at that run-rate, total revenue would be $9.06M. However, the pilot was 64% residential vs. 42% in our real base; adjusting for our actual commercial mix brings the pilot run-rate directly into our $5M–$7M range.)

---

3. Falsification Criteria & The 6-Week Test

#### What Would Prove This Challenge Wrong: 1. Commercial payers are willing to pay credit card surcharges (2.9%) at scale on invoices over $2,000, lifting commercial card share above 25%. 2. Mid-market/enterprise customers are willing to buy out or break existing processor contracts to consolidate inside Fieldline. 3. Commercial customers will accept basis-point pricing on ACH (e.g., 0.5% capped at $25) rather than a flat transaction fee.

#### The Cheapest 6-Week Test ($0 Eng, 1 Ops/Sales Lead): Instead of committing three engineering squads, run a zero-code commercial pricing test: 1. Target Group: 40 non-pilot customers with heavy commercial mix (HVAC/commercial plumbing) invoicing property managers. 2. Execution: Issue invoices using off-the-shelf payment links provided directly by our payments partner (dashboard-configured, zero Fieldline engineering). 3. Intervention: Enable Pay-by-Link on 500 commercial invoices ($2,000+) across two cohorts: * Cohort A (Standard): 2.9% fee passed to payer or absorbed by merchant. * Cohort B (Convenience ACH): $5 flat fee or 0.5% fee for direct bank integration. 4. Success Threshold to Validate Plan: If card volume on commercial exceeds 20% or ACH basis-point monetization is accepted without client backlash, the CEO's revenue model becomes viable. If commercial card adoption remains under 8%, the thesis is conclusively disproven.

---

4. Recommended Strategic Pivot

Pausing the scheduling rewrite is an unacceptable risk. That rewrite addresses the #1 driver of churn among customers with >50 technicians—a segment that cost us $1.9M in ARR last year alone. Churning enterprise SaaS ARR to pursue low-margin payment processing right before a Series raise will impair our valuation multiple.

We should adjust our strategy as follows:

``` +-----------------------------------------------------------------------------------------------+ | Proposed Engineering & Resource Allocation | +-------------------------------------+---------------------------------------------------------+ | Current Plan (Paused Scheduling) | Recommended Allocation | +-------------------------------------+---------------------------------------------------------+ | Fieldline Pay: 3 Squads (9 mos) | Scheduling Rewrite: 2 Squads (Protects $1.9M+ ARR Churn)| | Scheduling Rewrite: 0 Squads (Paused)| Fieldline Pay (Residential MVP): 1 Squad (6 mos) | | Commercial Discovery: None | Product/Finance: Commercial Working Capital Discovery | +-------------------------------------+---------------------------------------------------------+ ```

#### 1. Allocate 1 Squad to Fieldline Pay (Residential Focus) Package an MVP pay-by-link flow exclusively for residential jobs ($410 avg invoice, 71% card share). One squad can ship this within two quarters using out-of-the-box partner UI. This captures the high-margin, viable portion of payments (~$3.0M–$4.0M ARR) without over-investing.

#### 2. Fully Fund the Scheduling Rewrite (2 Squads) Protect the core $41.0M SaaS business. Retaining our 50+ tech accounts protects enterprise ARR and maintains our clean SaaS growth story for the Series raise in 14 months.

#### 3. Monetize Commercial Cash Flow, Not Processing (The Real Opportunity) 17 of 22 interviewed customers cited commercial float (waiting 52 days on net-45/60 while funding $200k payroll) as their single biggest problem. Nine stated they would gladly pay a fee to get paid faster. * Rather than fighting over a $1.60 ACH fee, evaluate accelerated invoice settlement (e.g., 1.5%–2.0% fee for Net-2 payout vs. Net-52, balance-sheet funded via partner). * Earning 1.5% on even 20% of our $2.8B commercial GMV yields $8.4M in high-margin fintech ARR by solving an acute customer pain point.

Summary

Let us present the board with a defensible plan: secure our core SaaS ARR, deploy 1 squad to capture ~$3M–$4M in residential payments, and test commercial invoice financing to solve our customers' true cash flow crisis.

Claims the judge couldn’t find in the brief

  • 30% of total GMV, or about $1.43B, is contractually inaccessible until 2028 because 71 of the 115 largest accounts are locked in.
  • Accessible GMV can be split 42% residential and 58% commercial, and pilot card shares can be combined with assumed ACH/check splits to produce blended take rates.

Grades and run details

Decision model 91 · LLM judge 6 of 12 checks
Decision model checks
  • passUses the supplied evidence correctly21%
  • passAddresses the actual decision97%
  • partialRespects explicit constraints47%
  • passIdentifies material uncertainty100%
  • partialAvoids unsupported claims33%
  • passProduces the required deliverable74%
  • passFinds the load-bearing assumption100%
  • passRe-estimates the revenue correctly44%
  • passSays what would prove it wrong100%
  • passReshapes the bet from the evidence100%
  • passTigers, not paper tigers90%
Run
Run
#1
API response time
51 s
Submitted
1 Oct 2026

Usable with a quick edit11 of 11 checks passed

The memo is complete and well-supported; it could be used with only minor wording edits.

Output

To: Priya Raman; CEO; CFO; Head of Sales From: Staff PM Subject: Fieldline Pay: challenge the revenue thesis before committing three squads

Recommendation

Do not commit three squads for three quarters or pause the scheduling rewrite. Authorize a six-week commercial test using the existing pilot product and partner.

Embedded payments may be worth building. The evidence does not support presenting $24M as an expected month-24 revenue run-rate. My scenario range is approximately $2–$10M annualized, with $10M an optimistic case—not a base case.

1. The unsupported assumption: adopted invoice dollars yield 0.7%

The plan’s most consequential assumption is that the invoice value belonging to adopting customers becomes payment volume earning a blended 0.7% net take.

That is card economics applied to all invoices. It conflates three things: adopting Fieldline Pay, routing payments through it, and choosing a profitable payment method.

The available evidence contradicts it:

  • Only 19% of recorded payment value is card. ACH is 44%; checks and cash are 37%. These observations cover 30% of customers, so representativeness remains unproven.
  • ACH does not yield 0.7%. We earn $1.60 per payment. At the average commercial invoice of $3,800, that is 0.042%; at the residential average of $410, 0.390%.
  • Commercial work is 58% of invoice value. Even in the pilot, commercial card share reached only 6%, versus 71% for residential. A 2.9% card fee on a $3,800 invoice is about $110, before the fixed charge. Sales and interviews both indicate resistance to that fee.
  • The pilot overweights our best payments segment: 64% residential versus 42% across Fieldline. Tradesly’s roughly 80% residential customer mix makes its revenue share a poor benchmark for ours.

Volume concentration compounds the error. The largest 115 customers supply 48% of invoice value; 71 have processor contracts, mostly through 2028. We do not know those 71 customers’ exact volume, but cannot assume their invoices are available.

Consequently, 70% customer adoption does not establish 70% volume capture. The $2.1M average also obscures this concentration: the median is $640k, and customers outside the largest 5% average only $1.15M.

2. Re-estimate: approximately $2–$10M annualized

Use:

Revenue = eligible invoice value × adoption × routed share × payment-method yield.

The following scenarios assume adopters route all eligible invoices through Pay. That is generous. They use today’s customer base, not unsupported customer growth, and are scenarios rather than a statistical confidence interval.

Conservative scenario: approximately $2.3M

Assumptions:

  • Exclude the entire largest-5% cohort pending evidence of access. This is a conservative scenario, not a claim that all 115 are contractually blocked.
  • Remaining invoice value: $4.83B − $2.32B = $2.51B.
  • Adoption: pilot’s 61%.
  • Retain today’s 19% card and 44% ACH value shares; checks and cash earn nothing.
  • Value ACH at the commercial invoice size. This produces the lower ACH yield.

Blended yield:

19% × 0.7% + 44% × ($1.60 ÷ $3,800) = 0.152%.

Revenue:

$2.51B × 61% × 0.152% ≈ $2.3M.

This assumes the remaining cohort has the overall payment mix; the pack does not provide its actual mix.

Optimistic scenario: approximately $10.3M

Assumptions:

  • All $4.83B is accessible, despite processor contracts.
  • 70% adoption also captures 70% of invoice value.
  • Pilot card conversion transfers to Fieldline’s actual job mix.
  • Every non-card dollar becomes ACH: no checks, cash or external payments.

Card value share:

42% × 71% + 58% × 6% = 33.3%.

Blended yield, using job-specific invoice sizes:

33.3% × 0.7% + [42% × 29% × ($1.60 ÷ $410)] + [58% × 94% × ($1.60 ÷ $3,800)] = 0.304%.

Revenue:

$4.83B × 70% × 0.304% ≈ $10.3M.

Even this unusually favorable case is 57% below the CFO’s $23.7M.

A separate cross-check is the pilot’s actual monetization: 1,610 adopters × $5,630 = $9.1M. That is not a forecast: the pilot is residential-heavy, and we lack its invoice-volume denominator. But it does not validate $24M.

The range could fall below $2M if adoption or routing disappoints. We lack the data to assign probabilities.

3. What would prove this challenge wrong?

To generate $24M from $4.83B, Fieldline needs portfolio-wide annual net yield of approximately 0.50%. At 70% volume capture, captured payments must yield approximately 0.71%.

We would need evidence of either:

  1. Much more accessible, routed, high-margin card volume than today’s mix and pilot suggest; or
  2. A demonstrably profitable additional fee or product customers will actually pay for.

Adoption percentages, enthusiasm and competitor revenue shares would not suffice.

Cheapest six-week test

Use the existing pay-by-link product and partner; no new platform build.

Recruit approximately 50 non-pilot customers, stratified by invoice volume and residential/commercial mix, including a deliberate sample of large accounts with processor contracts. Weight results by invoice dollars, not customer count.

For each, establish contractual access and offer Pay at intended production pricing. Measure:

  • Activation and actual routed invoice value;
  • Card/ACH/check mix, invoice sizes and realized net revenue;
  • Payer refusals, especially commercial surcharge refusals;
  • Large-account willingness and ability to switch.

Commercial invoices take 52 days to pay on average. Include existing invoices due during the test, not just newly issued invoices, and report unpaid invoices separately rather than assuming conversion.

The test passes only if observed economics and credible volume-access commitments support a transparent path to $24M. A small test cannot prove 18-month adoption, but it can cheaply falsify the unit economics or access thesis.

4. Change the bet

Keep the scheduling rewrite staffed. It addresses the top-cited churn reason in a segment that lost $1.9M ARR last year; postponing it has a concrete opportunity cost ahead of our raise.

If the test supports attractive economics, fund a narrower, stage-gated residential payments rollout—not the current commitment.

Separately, test commercial customers’ willingness to pay for faster collection. Seventeen of 22 interviewees identified commercial payment delays as their biggest cash problem; nine would pay to get paid faster. Payments acceptance does not itself solve net-60 terms. Explore collections workflows or partner-funded acceleration before underwriting a financing business.

Finally, reset the board’s expectation now: $24M is an unvalidated upside hypothesis, not an evidence-backed plan.

Grades and run details

Decision model 100 · LLM judge 12 of 12 checks
Decision model checks
  • passUses the supplied evidence correctly53%
  • passAddresses the actual decision100%
  • passRespects explicit constraints57%
  • passIdentifies material uncertainty100%
  • passAvoids unsupported claims53%
  • passProduces the required deliverable84%
  • passFinds the load-bearing assumption100%
  • passRe-estimates the revenue correctly35%
  • passSays what would prove it wrong50%
  • passReshapes the bet from the evidence100%
  • passTigers, not paper tigers98%
Run
Run
#1
API response time
60 s
Submitted
29 Sept 2026

Check by check

Where the outputs differ comes first. Open a check to read the judge’s reasons. “Mixed” means the two graders disagreed.

Where they differ 5

Uses the supplied evidence correctlyMixedRight
Gemini 3.8 Flash · API

The memo uses several unsupported current-state assumptions, especially the $1.43B locked GMV figure and the accessible GMV/payment-method splits.

GPT-6.1 Sol · API

Every factual figure used comes from the supplied pack or follows directly from its arithmetic; no current-state fact is invented.

Respects explicit constraintsWrongRight
Gemini 3.8 Flash · API

The memo appears to exceed the 1,200-word limit and includes heavy tables and formatting that make it less usable as a concise exec pre-read.

GPT-6.1 Sol · API

It is a memo addressed to the named exec readers, covers all requested sections, and is within the 1,200-word limit.

Avoids unsupported claimsWrongRight
Gemini 3.8 Flash · API

It presents several estimates and causes as established facts, including the locked-GMV amount, accessible mix, and that pilot adjustment lands directly in the $5M–$7M range.

GPT-6.1 Sol · API

Interpretations and forecasts are clearly framed as assumptions or scenarios, not established fact.

Produces the required deliverableMixedRight
Gemini 3.8 Flash · API

It is a memo with the required sections, but it is too long and contains material arithmetic assumptions that would need rechecking before use.

GPT-6.1 Sol · API

The deliverable is a complete pre-read memo usable by the exec team with light edits.

Re-estimates the revenue correctlyMixedRight
Gemini 3.8 Flash · API

It lands in the right range, but the working relies on unsupported locked-GMV and payment-mix assumptions rather than a clean recalculation from supplied data.

GPT-6.1 Sol · API

It shows arithmetic landing in $2.3M to $10.3M with a $9.1M pilot cross-check and explains the pilot's residential-heavy bias.

All got right 6

Addresses the actual decisionRightRight
Gemini 3.8 Flash · API

It commits early to right-sizing the bet, funding the scheduling rewrite, limiting Fieldline Pay to residential, and testing commercial cash-flow monetization.

GPT-6.1 Sol · API

It commits early to not committing three squads and authorizing a six-week test, and specifies what result would change that.

Identifies material uncertaintyRightRight
Gemini 3.8 Flash · API

It names the key unknowns—commercial card acceptance, contract breakability, and ACH basis-point pricing—and gives six-week thresholds.

GPT-6.1 Sol · API

It names the unknowns (representativeness of payment data, large-account volume access, actual mix) and resolves them with a bounded test.

Finds the load-bearing assumptionRightRight
Gemini 3.8 Flash · API

It correctly makes the 0.7% blended take rate applied to all invoice value the central challenge and supports it with payment-mix and unit-economics figures.

GPT-6.1 Sol · API

It makes the 0.7% blended take applied to all invoice value the central challenge, backed by payment-mix and unit-economics figures.

Says what would prove it wrongRightRight
Gemini 3.8 Flash · API

It specifies a cheap six-week commercial pay-by-link test with concrete thresholds that would change the conclusion.

GPT-6.1 Sol · API

It names a six-week test with cohort, metrics and economics threshold around 0.71% captured yield needed to support $24M.

Reshapes the bet from the evidenceRightRight
Gemini 3.8 Flash · API

It keeps residential card payments and pivots the commercial opportunity toward faster payout/working capital, grounded in interview evidence.

GPT-6.1 Sol · API

It proposes keeping the scheduling rewrite, a stage-gated residential rollout, and testing commercial faster-payment demand, grounded in the evidence.

Tigers, not paper tigersRightRight
Gemini 3.8 Flash · API

It ranks the take-rate and contract-access issues as material, treats Tradesly as a residential-mix comparison, and surfaces the churn/valuation risk of pausing the scheduling rewrite.

GPT-6.1 Sol · API

It triages take rate and volume access above secondary risks and dismisses the Tradesly analogy with the residential-mix reason.

Results

Every setup we’ve tested on this task, across all cases and repeats, graded on the current checklist. Calibrated: the graders match our PM on 88% of checks.

#Model · HarnessTask scoreDecision modelLLM judgeRunsCritical failures
1GPT-6.1 SolwithAPI100.095.82None
2GPT-6 AstrawithChatGPT93.295.82None
3GPT-6 LunawithAPI97.791.72None
4Sonnet 5.5withAPI90.975.02None
5Gemini 3.5 Flash-LitewithGemini88.675.021 capped
6Opus 5.5withClaude93.291.721 capped
7Gemini 3.8 FlashwithAPI93.237.521 capped

About the task

The PM job

Pressure-testing a proposal before committing a team to it.

Why it matters

The useful critic finds the one assumption everything rests on. Theatrical negativity is easy to generate and useless in a planning meeting.

What good looks like

  • Identifies the load-bearing assumption
  • Separates the risks that could kill it from the ones that only look scary
  • Uses the supplied evidence, not generic risks
  • Proposes the cheapest way to test the assumption

Deliberately not measured

  • Tone
  • Number of objections raised
Capability tested

Evidence-based critique

The failure we’re looking for

Theatrical negativity without evidence

Grading

Decision model and LLM judge, calibrated against a blind PM review

Variants

Vanilla prompt (core) · With Roast Me skill · Staff level: a company bet with a long evidence pack

This task measures the whole setup. Tools, instructions and skills in the harness do real work here, so read the harness as carefully as the model name.