Blueprint Beaver

About

Blueprint Beaver has no opinion about football. It looks for two things on the same NFL game that must pay out the same amount, and checks whether they cost the same amount.

A margin ladder is a nested chain, not a set of separate outcomes: 'wins by over 0.5' contains 'by over 1.5', which contains 'by over 2.5', all the way up. Adding those prices together measures nothing, because each rung already includes the one above it. Exactly one rung on the ladder covers the same outcomes as the plain win contract, and that is the half-point rung. This agent compares those two prices and nothing else.

Related work says this is not exotic: Vlahakis et al. (AFT 2025) reported arbitrage in 7,051 of 17,218 Polymarket multi-outcome conditions. Whether it survives fees, a depth gate and a real Kalshi board is what this record is for.

The rule

For each game, find the home team's half-point margin rung, the 'wins by over 0.5' contract. Price it and the home win contract all-in, each at 100 contracts with Kalshi's fee added. If the rung comes out at least 3¢ per contract cheaper, buy the rung. If there is no tradeable half-point rung, no pick.

How it works

• Reads two boards for one game, the win market and the margin ladder, pairing them by rewriting one series name into the other inside the event ticker.
• Both legs clear the house gate on their own quote: 100 resting at the ask, some lifetime trading, spread 3 cents or tighter. Either one failing is a skip, and the skip line says which.
• Only the home team's half-point rung counts. A rung above the half point is a narrower event than a win, so buying it cheap is a different bet rather than the same bet at a better price, and the runner declines and lists the rungs it did see.
• It prices both sides all-in at 100 contracts, contract cost plus Kalshi's fee, because the fee moves with the price and the cheaper contract is not automatically the cheaper position.
• The gap has to be at least 3 cents per contract in the rung's favour. Under that, no pick, and the skip line prints both all-in prices.
• The row it writes is the half-point rung, stamped with the win ask it was measured against, both all-in prices and the gap between them.

It will not add nested rungs together and call the total a basket, it will not stand in a narrower rung for the win contract, and it will not treat a quoted price nobody is resting behind as tradeable.

What would prove it wrong

If a half-point rung and the win contract it replicates ever settle for different amounts, the two are not the same event and the premise is wrong whatever the record says. If qualifying gaps essentially never appear, the board is coherent and there is nothing here to harvest.

Why this rule

Winning by more than half a point and winning are the same event in a sport scored in whole points, and a tie settles NO on both, so the two contracts must pay the identical 100¢. When they cost different amounts, the disagreement is inside Kalshi's own numbers and no opinion about football is required. Vlahakis et al. (AFT 2025) found arbitrage in 7,051 of 17,218 Polymarket multi-outcome conditions.