Trade Evaluation

Trade Evaluation: Two-Sided Assessment

Judge a specific trade from both rosters' perspectives. Raw player value is the start, not the verdict — value only counts when it reaches a starting lineup.

Step 1: Load context

Read leagues.md from the project root first — the fields that matter here are scoring, starting slots, roster/bench size, playoff weeks, trade deadline, and whether trades face a veto vote. If the file is missing or blank, ask and suggest running fantasy-league-setup:league-config. If more than one league is defined, use the one marked (default).

Gather both full rosters, both records/standings, and the exact terms. Without the other team's roster only half an evaluation is possible — say so and evaluate provisionally.

For any in-season evaluation, make the timing explicit:

• State the verdict as of a concrete date/time.
• Refresh injuries, suspensions, depth-chart changes, and any same-week news if the inputs are stale or undated. Trade advice that turns on a Tuesday hamstring report should not be delivered as if it were timeless.
• For any consequential injury-based value swing, require both the official team/game status and a second credible source. One unsupported report is not enough to move a player multiple tiers.

Step 2: Who originated the offer? — ask this first

An incoming offer is adversely selected. The proposer built it after looking at both rosters and concluded it helps them. That is not bad faith; it is what proposing means. It does change the prior:

• Offers you received: require a clearly positive edge, not merely an even one. "Even" plus adverse selection is a small loss on average.
• Offers you constructed: even is genuinely fine, and mutual benefit is the normal shape of a good trade.

This is the step most trade advice skips, and it flips the verdict on marginal incoming offers.

Step 3: Raw value pass

Assign each player a rest-of-season value from projections the user supplies, a consensus source read from the browser (name it and the date), or reasoned judgment (label it as such). Sum both sides. Live platform source routing. Honor a browser the user explicitly names. If leagues.md records a Preferred browser, use that when it has a signed-in session for the platform. Otherwise use any authenticated browser the current assistant already has. For Yahoo league data, prefer an authenticated browser over a connector. If a Yahoo connector returns 403, unauthorized, or an equivalent authorization failure, do not retry it during the same task. For non-Yahoo platforms, use a purpose-built connector when it is available and returns complete current data; otherwise use the browser. Read league rosters, the free-agent pool, standings, transaction history, and any rankings site directly instead of making the user paste them. Timestamp live data and name the source. The session rules from roster-ops apply unchanged: the user's session is the auth; never ask for, read, store, or type credentials; use the visible UI rather than platform endpoints; and stop and hand back on any login, 2FA, captcha, consent, or unusual-activity screen. If no usable live source exists, state the access gap and do not fabricate league-specific analysis.

This skill is read-only. Reading a page needs no confirmation, but never click anything that changes a roster, files a claim, or sends an offer from here — that is what the roster-ops skills and their confirmation gates exist for.

Interpret the gap in broad bands rather than fake precision, and distinguish an opening anchor from a final executable offer:

• Under roughly 5% — genuinely indistinguishable. Decide on lineup fit alone.
• Roughly 5–15% — a real edge you cannot measure confidently. Take it when the lineup-delta test agrees.
• Well beyond that range in a final executable offer — usually lopsided enough to call out bluntly unless keeper rules, forced cuts, or playoff timing explain it.

A drafted opener from trade-analyzer:trade-finder can intentionally start wider than an eventual acceptance band because it is an anchor, not a final signed deal. Do not call every aggressive opener a "fleece" unless the user is actually considering accepting or sending it as the last word.

Widen these bands to match measured disagreement between projection sources when more than one is available.

Step 4: Lineup delta — the real test

For each team, compute the optimal weekly starting lineup before and after, using this league's slots:

• Lineup delta = projected starting-lineup points after − before. A WR4 traded away costs a 3-WR team real points and a 2-WR team nothing.
• Optimize those lineups globally across all eligible slots; do not score the deal with greedy slot fill that strands a better total arrangement.
• Bench players are not worth zero — that shorthand is only true in very shallow leagues. With 6–8 bench spots, a plausible starter carries roughly 20–35% of his projection in option value: injury insurance, bye coverage, and trade currency. Only genuinely unplayable pieces round to zero. This matters most on 2-for-1s, which transfer risk as well as value: after any consolidation, ask "if my starter at this position goes down, who starts?"
• In any multi-player deal, include the forced-cut and waiver-replacement tax. If a 2-for-1 means the receiving team must cut someone, price the loss of that cut player and the value of the best likely waiver replacement rather than pretending the extra roster spot is free.
• Check asset legality before blessing the structure: pick/FAAB trading, keeper rights, IR/offseason designations, recently added players, and position-cap rules all change whether a mathematically good construction can actually be executed.
• Run byes and the configured playoff weeks separately from the season average when the deadline is near — a September trade is about 12 weeks, a November trade about 3.
• Injury status is usually the largest in-season value swing. Price a hurt player as games missed × per-game value, discount for re-injury risk and ramp-up, and note that a player returning in week 13 can be worth far more to a contender than his season-average value implies.

Translate the result into something decidable: roughly +1 point per week ≈ +1% win probability per game against a typical lineup. A +1.2/week delta over five remaining weeks is about +0.06 wins — real, but small enough to weigh against execution risk.

Step 5: Standings and rivalry context

• Contender: values the configured playoff weeks and ceiling; should pay a premium for the best player and for playoff-schedule advantages.
• Bubble team: values the next 3–4 weeks; weight near-term delta 2:1. A deal that wins rest-of-season but loses the next three can eliminate them before it pays.
• Eliminated/rebuilding: in keeper formats, values keeper-eligible pieces (route to draft-strategy:keeper-evaluation). In pure redraft there is little reason to trade at all.
• Determine these from playoff probability and seeding scenarios, not record alone — a 7-3 team locked into a bye and a 7-3 team fighting for the last spot should behave very differently.
• Are you arming a rival? Check two things the raw math misses: whether this team is competing with you for a playoff spot, and whether you play them in the remaining weeks. Upgrading the lineup of the team chasing your seed — or the team you face next Sunday — is a real cost.

Step 6: Verdict

Deliver Accept / Decline / Counter, a confidence level, and two or three sentences of reasoning. If Counter, say what change flips it, then suggest trade-analyzer:trade-negotiation. Report both sides' win conditions honestly — mutual benefit is what fair trades look like, and saying so builds the credibility that gets future deals accepted.

If the league uses veto votes, note when a fair deal looks lopsided, since appearance is what gets vetoed.

Worked example (fictional)

"Gridiron Gazette," week 10. As of Thursday 7:00 PM ET, both rosters, standings, projection source, and platform trade rules have been refreshed; no unresolved injury designation materially changes the price. User (7-3, contender, thin at RB) receives an offer: get RB Quincy Marsh + WR Deion Marsette, send WR Cassius Bell. Opponent is 4-6 (bubble), starts 3 WR, RB-surplus.

• Origination: they proposed it, so the bar is a clearly positive edge, not break-even.
• Raw value: user ahead by roughly the high-teens on current projections — enough to favor the user on paper for a final offer, while still acknowledging source noise.
• Lineup delta, user: Marsh upgrades a dead RB2 (+4.1/wk); losing Bell drops WR2→WR3 (−2.9/wk); Marsette is bench depth (+0 to the lineup, but real option value). Net +1.2/wk, and Marsh's playoff schedule is soft.
• Lineup delta, opponent: Bell upgrades their WR3 (+3.4/wk); Marsh was their bench RB3; Marsette was their WR5 (−0.4/wk). Net +3.0/wk.
• Rivalry check: they're 4-6, three games back, and not on the user's remaining schedule. Arming them is low-risk.

Accept (moderate-high confidence). As a final executable offer, it clears the adverse-selection bar: the value edge is meaningfully in your favor and it fixes your RB slot. But be clear-eyed about why they offered: they gain more per week than you do (+3.0 vs +1.2), because near-term lineup points are exactly what a bubble team needs. Accept because it's positive for you, not because you "won" every line of the ledger.

Note the verdict does not revert to the raw-value ledger the moment lineup delta is inconvenient — it reports both and says which one drove the decision.