The Broncos began the game with a 54 percent chance to win, but after a number of big plays, they increased their win probability to 80 percent by the half. The Patriots mounted three long drives in the fourth quarter, but after two fourth-down stops (combined minus-19 win probability added) and a failed two-point conversion attempt (minus-25 win probability added), the Broncos clinched a 20-18 victory.
Below are the five most impactful plays of the game (as measured by ESPN's win probability model) ordered chronologically. Many of the plays were made by the Patriots' offense in the fourth quarter, but ultimately the combined win probability that the Broncos amassed in the first half was too much to overcome.
2:27 First quarter: Denver fumble on backward pass
Win probability change: From 74 percent to 63 percent (minus-11 WPA)
Originally called an incomplete pass, Manning's backward pass to Ronnie Hillman was challenged and overturned. The Patriots got the ball on the Denver 22 and went on to score their first touchdown of the game.
8:10 Fourth quarter: Julian Edelman 19-yard reception
Win probability change: From 15 percent to 26 percent (plus-11 WPA)
On third-and-10, Brady completed a 19-yard pass to the Denver 25. Four plays later, with the Patriots trailing by eight, the Broncos stopped the Patriots on fourth-and-1, the sixth-biggest WPA play of the game.
1:34 Fourth quarter: Rob Gronkowski 40-yard reception
Win probability change: From 3 percent to 19 percent (plus-16 WPA)
On fourth-and-10 with the game on the line, Brady hit Gronkowski over the middle for a 40-yard gain to the Denver 10.
0:17 Fourth quarter: Gronkowski 4-yard touchdown
Win probability change: From 10 percent to 25 percent (plus-15 WPA)
The Patriots' chance to win had again dropped below 10 percent before Gronkowski's miraculous catch on fourth-and-4 to bring the Patriots to within two at 20-18.
0:12 Fourth quarter: Broncos stop 2-point attempt
Win probability change: From 25 percent to less than 0.1 percent (minus-25 WPA)
The Patriots had a 25 percent chance to win before their potential tying 2-point attempt. Bradley Roby intercepted Brady's pass to seal the victory for the Broncos.
Win probability measures the chance that a team will win a game in progress, given a particular combination of circumstances including score, time remaining, field position, down and to-go distance. Win probability is based on a model built on actual NFL outcomes from recent seasons that featured similar circumstances.