You do not buy a player. You take on his contract and send capital.
A trade is an exchange of contracts and capital under the cap, priced on both sides of the ledger, with draft capital valued two ways.
You inherit the deal. Cap space and capital go the other way.
A player is not bought and sold for a fee. A team that trades for a player inherits his existing contract, his base salaries, his future obligations, his guarantees, and his cap hits across the remaining years, and the currency of the trade is cap space and draft capital.
The same player is a different trade to two teams: a contender with cap room inheriting a cost-controlled deal is capturing surplus, a capped-out team inheriting a top-of-market deal is buying negative surplus at a capital cost. The player's on-field value is one input, but the object is the contract. Trade the contract, price it under the cap, and send capital, not cash.
Illustrative on the real contract-as-asset rule (the acquiring team inheriting the contract and guarantees, the currency as cap and capital not cash, the trade cleared against the cap, the contract priced into each team's cap position). Composite trade, demonstration figures.
The player leaves. The accelerated bonus does not.
Trading a player away does not clear his contract off the books. The trading team is relieved of his future base salary and roster bonuses, but it keeps the remaining prorated signing and option bonus, which accelerates onto its cap as dead money. The accelerated proration cannot be sent away with the player.
This is the same limited-guarantee, bonus-heavy structure read from the trading side. A trade that looks like clean cap relief can carry a bill that eats most of the savings, and the engine will not let the salary relieved stand in for the net cap effect. Price both sides of the ledger, the money shed and the money kept.
Illustrative on the real trade-side dead-money layer (the salary relieved versus the accelerated bonus kept, the dead-money cost of moving a heavily-bonused contract, the pre- and post-June-1 treatments). Composite trade, treatment current-as-of.
The market chart is steep. The surplus chart is flat.
Draft picks are the currency of a trade, and the engine values them two ways and keeps them distinct: the traditional trade-market value teams actually trade against, steep and top-heavy, and the analytical surplus value a disciplined team builds on, far flatter and peaking in the mid-first-to-second round.
The engine must still clear a trade against the market chart, because that is the price the other team trades at, but it reports the surplus chart alongside it. Trading down is not always right, a specific player worth the premium changes the math, but the default mispricing runs one direction, and the engine names it every time. Clear the trade at the market, but build on the surplus.
Illustrative on the real draft-capital layer (the steep trade-market chart against the flatter surplus chart, the mispricing at the top of the first round, the trade-down-for-surplus move, the future-pick discount and multi-year stock). Composite picks and charts, held in the Pro Cap Reference.
Price the contract, count the dead money, and trade the capital against the surplus, not the fee.
Trade the contract, price both sides of the ledger.
Trades Intelligence models a trade as an exchange of contracts and capital under the cap, prices the inherited contract into each team's cap position, computes the dead money the trading team keeps, and values the draft capital against the surplus chart, not just the market chart.