Here’s what math says on LA Chargers coach Staley’s 4th-down decisions vs. KC Chiefs
Chargers coach Brandon Staley made a significant call Thursday night, deciding to go for it on fourth-and-goal from just outside the 1-yard line with 3 seconds left in the first half, L.A. leading the Kansas City Chiefs, 14-10.
And though the result didn’t go the Chargers’ way — quarterback Justin Herbert’s pass was deflected by Chiefs safety Daniel Sorensen for an incompletion — the math behind the decision was sound.
ESPN’s estimations give some insight. Even from the 2-yard line, ESPN analytics writer Seth Walder tweeted that the site’s numbers gave the Chargers a 59.7% chance of getting the touchdown and a 98.4% shot at making the field goal. Walder said the Chargers would’ve needed an expected 44% success rate on the play to make the decision mathematically sound, and that it would’ve been a wise choice on any fourth-and-goal scenario up to four yards.
Walder went on to talk about the math behind the decision using simple multiplication. A touchdown is worth 6.95 points on average in the NFL, compared to a field goal that is always worth three. That means over time, going for the touchdown will net the Chargers 4.15 expected points (6.95 times 59.7%) while a field goal try will gain 2.95 points (3 times 98.4%).
So while analysts and fans can argue the value of momentum, the raw math says Staley would be punting more than a point away if he chose to stick to conventional wisdom.
The Fourth-Down Bot developed by The Athletic’s Ben Baldwin supported Walder’s conclusions, though it used the official box score, which assumed the Chargers were on the 1-yard line.
Those numbers indicate that, over time, the Chargers would win 65% of the time if they went for it in that situation and 63% if they kicked the field goal.
The results didn’t go Staley’s way, but they made history. On Los Angeles’ first drive, Staley also went for it on fourth-and goal from the Chiefs’ 5 and failed. According to ESPN Stats & Info, it was the first time since at least 2000 that an NFL team had failed a fourth-and-goal-to-go at least twice before halftime.
Regardless of outcome, Staley was seeking the type of small edge that coaches are less likely to abandon as fourth-down aggressiveness becomes more mainstream. Heading into this week, Staley was No. 1 in EdjSports’ rankings that gauges coaches based on their fourth-down decisions and how they affected their teams’ probability of winning each game.
KC coach Andy Reid said after the Chiefs’ 34-28 overtime win that he expected the aggressiveness from Staley.
“That’s what they do. They do it with everybody. It wasn’t just us,” Reid said. “We knew that coming into the game that if it’s fourth down, their head coach has said it: He’s said that’s like third down to them. But you’ve got to stop them, so our guys got enough of those (stops) to help.”
Those two weren’t the only critical fourth-down calls in Thursday’s game. Here’s a look at each moment and what Fourth-Down Bot’s verdict was on the decision.
Chargers go for it on fourth-and-goal at the Chiefs’ 5, first quarter, Game tied 0-0
Bot verdict: Correct decision
The Chargers had a 43% chance of winning by going for it, compared to 40% with a field-goal try.
Chargers go for it on fourth-and-1 at the Chiefs’ 33, second quarter, Chiefs lead 10-7
Bot verdict: Correct decision
The expected success rate on converting fourth-and-1 (73%) and making a 50-yard field goal (70%) are nearly equal, so continuing to go for the touchdown makes more mathematical sense. Herbert picked up the first down, and sure enough, the Chargers scored a touchdown on this possession.
Chargers go for it on fourth-and-2 at the Chiefs’ 28, third quarter, Chargers lead 14-13
Bot verdict: Correct decision
The Bot once again prefers going for a short conversion rather a long field goal (55% win percentage vs. 51%). Herbert’s incomplete pass turned it back over to KC.
Chiefs go for it on fourth-and-goal at the Chargers’ 1, third quarter, Chargers lead 14-13
Bot verdict: Correct decision
This was the easiest call of the bunch. The Chiefs are expected to score a touchdown 71% of the time here, and although receiver Mecole Hardman was open, Patrick Mahomes missed him.
Chargers go for it on fourth-and-1 at the Chiefs’ 11, fourth quarter, Chargers lead 14-13
Bot verdict: Correct decision
Staley shifted his team’s expected win probability to an expected 65% by going for it, as opposed to 59% with a field-goal try. The Chargers converted before fumbling three plays later.
This story was originally published December 16, 2021 at 9:53 PM.
