How Often Football Underdogs Win: 1,391 NFL and College Football Games at Kickoff Prices on Polymarket

A Polymarket moneyline pays $1 a share on the team that wins, so a team at 30 cents is a 30% chance. We took each game's price at kickoff: the last point in Polymarket's public price history before the game started, a median of 0.9 minutes before. The favorite is the team priced above 50 cents at that moment, the underdog the team below it, and an upset is the underdog winning.

Every game was matched to ESPN's final score, season type and venue. ESPN listed all 679 NFL games and 1,043 of 1,049 college games, and Polymarket's settlement named ESPN's winner on every one of them except a 2024 preseason NFL tie. Preseason games are left out, 109 of them in the NFL.

We also left out 213 college games whose moneyline traded under $10,000. A market that thin can print a last price nobody could trade at size: the South Dakota Mines and Drake moneyline traded $946 in all. We set that floor after a first cut that kept every game, and the one result it changes is reported below.

The NFL sample is 569 regular-season and playoff games from September 6, 2024 to September 10, 2026, 25 of them in the playoffs. The college sample is 822 games from September 11, 2025 to September 12, 2026, 44 of them bowl and playoff games. 67 games were played at a neutral site; they count everywhere except the home and road split.

Rates carry a binomial half-width. The edge is the win rate minus the average kickoff price, and its interval resamples games.

NFL underdogs were priced at 33.10 cents on average and won 31.8% of 569 games, with a half-width of 3.83 points. That is 1.29 points short of the price, with an interval from minus 4.99 to plus 2.64. College football underdogs were priced at 25.84 cents and won 25.9% of 822, 0.08 points ahead of the price.

So upsets come at the rate the market charges for them: about one NFL game in three and one college game in four. The favorites mirror it, 68.2% in the NFL at 66.9 cents and 74.1% in college at 74.2 cents.

Split by the favorite's kickoff price, no band was reliably too high or too low. College favorites priced 90 cents or more, 157 games at 95.7 cents, won 94.3%, so about one in eighteen of them lost. NFL favorites at 80 to 90 cents won 87.0% of 54 games at 84.4 cents.

The widest miss was college favorites at 60 to 70 cents, 2.70 points short over 193 games, and its interval runs from minus 9.42 to plus 3.92. The NFL's 10 favorites at 90 cents and up all won, too few games to read.

Among moneylines that traded $50,000 or more, the lowest kickoff price for a winner was UMass over Rutgers on September 3, 2026, 37-21, at 2.6 cents: a winning share paid about 38 times its price. UCLA beat Penn State at 5.0 cents on October 4, 2025, and Oklahoma State beat Oregon at 5.5 cents on September 12, 2026.

The NFL's biggest was the Panthers over the Packers on November 2, 2025, 16-13, at 13.5 cents. The biggest playoff upset was the Commanders over the Lions on January 18, 2025, at 18.5 cents. The table lists eleven, with three college winners tied at 8.5 cents.

$1 on every NFL underdog at its kickoff price returned minus 5.85% before fees and minus 9.20% after Polymarket's sports taker fee, with an interval from minus 21.13% to plus 3.36%. In college football the same bet returned minus 2.38% before fees and minus 6.09% after. Backing every favorite came out near even: plus 0.23% in the NFL and minus 1.38% in college after the fee.

Every one of those intervals includes zero, so none of it is an edge to chase. What the numbers do show is the cost of long shots: the fee is 0.05 × price × (1 - price) per share, which takes about 3.7 cents of each dollar staked on a 26-cent underdog against 1.3 cents on a 74-cent favorite.

With neutral-site games left out, NFL home underdogs won 32.0% of 222 games at 35.4 cents, 3.38 points short, and NFL road underdogs won 31.5% of 333 at 31.4 cents. College home underdogs won 30.2% at 29.6 cents and road underdogs 22.8% at 22.9 cents. None of the four clears zero, so the market already prices where a game is played.

The first cut, with every college game kept, told a different story: road underdogs priced at 20.4 cents won 19.3% of 658 games and $1 on each lost 23.44% after the fee, an interval that excluded zero. Most of that loss came from the 167 of those games whose moneyline traded under $10,000, where road underdogs were priced at 13.2 cents and won 9.0%. With them out, the loss is 12.81% with an interval from minus 34.20% to plus 12.72%.

It covers moneylines only. It does not model injuries, weather or rest, and it does not say whether a spread bet on the same underdog would have done better.

The kickoff price is the last point in Polymarket's public price history. A buyer pays the ask, which sits above that price by up to half the spread, plus the taker fee, and the fee here is today's schedule applied to every game.

The NFL sample is parts of three seasons and the college sample one season and the start of another, so price bands of 50 to 200 games carry half-widths of five to nine points. Games whose market settled on Polymarket without a recorded result in 0xinsider's database are not counted.

Treat the kickoff price as a fair estimate of the upset chance. An NFL underdog at 33 cents won about a third of the time, a college underdog at 26 cents about a quarter, and a college favorite at 96 cents lost about one game in eighteen.

So back an underdog when you have a reason to think the price is wrong about that game, not because upsets happen. Long shots make the fee and the spread count for more, so a limit order that rests on the book and fills, which pays no taker fee, matters most on the cheapest side.

The NFL board at 0xinsider.com/sports/nfl and the college football board at 0xinsider.com/sports/college-football list live and upcoming games with an active Polymarket market. Each card shows both teams' prices and chances, the price move over the last 24 hours, the kickoff time, and the top five holders on each side with their grades and football win rates.

Open a game for its event page, where the Markets section lists the moneyline beside the spread, total and prop families with each family's volume. The whale alerts feed at 0xinsider.com/whale-alerts shows every large trade as it fills. The guides at 0xinsider.com/learn/how-to-bet-on-nfl-polymarket and 0xinsider.com/learn/how-to-bet-on-college-football-polymarket cover every market on a game and how it settles.

Every number on this page comes from four published runs: a read-only export of the settled moneylines at 23:30 UTC on September 13, 2026, a match of each game to ESPN's public scoreboard, a pull of each game's kickoff price from Polymarket's public CLOB API, and an analysis script that reproduces every table from those three files. All of them are at github.com/0xinsider/research, under polymarket-sports-markets, in the files whose names carry the word football.

The universe is one settled full-game moneyline per NFL or college football regular-season or postseason game that traded $10,000 or more and settled on ESPN's winner. Expect the count to grow every week of the season.