Spurs vs. Bulls: O/U 236.5

Research grade

⚖️ NeutralUnder at 47%

No measured edge, which here means a loss: the plain consensus (5+ holders, 60 %+, held to resolution) lost −3.0 % a trade after costs out of sample in the full-year test (n 86,296, 95 % CI −3.6 to −2.4 %).

• ≤ Spread or totalOct 22 backtest: spreads and totals −14.5 % a trade in spring (95 % CI −27 to −1), +1.5 % in October: no edge.
• − BasketballFull year, out of sample: basketball lost −4.8 % a trade (n 1,747, 95 % CI −9.2 to +0.3); Oct 22 backtest: −12.0 % and −9.2 % in its two windows.
• + $100k+ behind an 80 %+ consensusNot confirmed. Oct 22 backtest: +13.2 % a trade (n 91), a small sample. Full year, out of sample: 80 %+ with $100k+ on the side −0.3 % a trade (n 835, 95 % CI −3.8 to +3.4): no edge.
• · Side priced 30–50¢Full year, out of sample: 0.30–0.50 lost −4.8 % a trade (n 16,830, 95 % CI −6.6 to −3.1), worse than the plain consensus.

The rules come from our Oct 22 2026 backtest (one entry per market, held to resolution, after a 1¢ half-spread and Polymarket's taker fees). Our full-year test without hindsight (Oct 26 2026) found none of them profitable out of sample, and the plain consensus lost −3.0 % a trade. The grade describes the market; it is not a forecast, not an edge and not advice.