In some ways, the Chargers performance was admirable given the circumstances. Tyrod Taylor was a late scratch so 6th overall pick Justin Herbert was tasked with starting his first NFL game against an offensive juggernaut in the Chiefs. Expecting a rookie quarterback to keep pace with Patrick Mahomes is a daunting task, but Herbert was up to it matching Mahomes' performance throughout the contest.
While it was nice to see the Chargers, led by Herbert, play well-enough to win against the Super Bowl favorite (according to the Vegas odds as of the writing of this post), the goal of any game is to win. A team that was not favored to be in the playoffs before the season started even with the addition of a third wildcard cannot afford to drop games where it is winning for the majority of the snaps, especially against a division foe. A couple of end game decisions by Chargers coach Anthony Lynn (who has been among the least aggressiveness head coaches on fourth downs and has had prior issues with clock management) peaked my interest and I wanted to check if they were contributing factors to the Chargers losing this game.
The first decision was kicking a 23 yard field goal from the Kansas City five yard line to put the Chargers up 20-17 with 2:27 left in the fourth quarter. My initial reaction was this was a mistake. The Chargers, as I mentioned above, were heavy underdogs going into the game. Scoring a touchdown in this situation would put them up seven (assuming they hit the ensuing extra point) and would give the Chiefs no room to win in regulation. The Chiefs, with 2:27 left, would have to score a touchdown to even get a chance at overtime. By kicking a field goal, the Chargers allowed the Chiefs an additional avenue to win the game. If the Chiefs were to score a touchdown, they would almost definitely win. To send the game into overtime, all they needed to do was kick a field goal. I went back through all the play-by-play data I had access to (back to the 1999 season) and isolated games where a team was in a similar situation as the Chargers. I filtered for games where a team kicked a field goal of less than 40 yards when they had less than six yards to go for a first down and there was between a minute and a half and three and a half minutes left in the fourth quarter. I had to make the time interval large enough to extract a large enough sample. Teams (of which there were 19) in the Chargers' situation won the game about 63.2 percent of the time and went to overtime 26.3 percent of the time. The issue I had when trying to do the same analysis with going for a touchdown was that every team in the Chargers situation decided to kick a field goal. To try to get around the issue, I looked at drives that started with between two and three minutes left in the fourth quarter and where the team on defense was up by seven points. I found 33 drives that met this criteria and the team on defense only won about 57.7 percent of the time.
This is not intuitive. How can a team have a worse chance of winning if it scores a touchdown? There are two issues. The first is sample size. The sample of teams that kicked a field goal in this very specific situation was 19 and they were only 33 teams in my touchdown sample. In both situations, making sweeping judgments based on such a small portion of all the games since 1999 is bound to lead to some faulty conclusions. The small samples also lead to factors heavily influencing the overall results of the samples, such as the specific teams involved. This brings me to the second issue: the teams involved. The Chiefs, since Mahomes became the starter, have scored a touchdowns on a shade over 40 percent of their drives. By kicking a field goal, the Chiefs would have the opportunity to essentially seal a win in regulation by scoring a touchdown. When you factor in the rate of drives that end in a field goal for the Chiefs, we are talking about a slightly greater than 50 percent chance that they either win the game or send it to overtime, the latter of which you would still favor the Chiefs to win . One might quibble that this does not account for the lack of time remaining (about two and a half minutes) but I would counter that the time constraint forces the Chiefs to have to throw the ball more than they would otherwise and the Chiefs passing offense with Mahomes has been among the most prolific in NFL history. When you consider my small sample analysis of teams in the Chargers situation and the team the Chargers were facing, I find it difficult to be too hard on Anthony Lynn in this spot. I can see the argument in either direction, so pinning the loss on that one decision might be a bit harsh. Furthermore, when using the win probability calculator at pro-football-reference, based on the changes in win probability for scoring a touchdown and kicking a field goal, the offense would have to be able to score a touchdown more than 57.4 percent of the time. This is higher than even the two point conversion rates. Thus, kicking the field goal was actually the correct decision here.
The second decision major decision by Lynn was much more indefensible. After winning the coin toss in overtime, the Chargers started their drive on their own 25 yard line after a touchback. The Chargers ran the ball on first and second down then threw the ball for six yards, leading to a fourth and one on their own 34. Lynn had two choices: go for it on fourth down or punt. By going for it and not converting, the game would effectively be over because all the Chiefs would have to do was kick a field goal to end the game. A field goal from the 34 would be about 51 yards, which has been converted at a 56.4 percent rate since 1999. At any distance closer, that percentage increases. Move the ball 10 yards and the rate is 78.3 percent. Another 10 and it's 83.4 percent. Obviously a touchdown would end the game also. Basically, no matter how you slice it, going for it and not converting almost definitely means a loss. Punting the ball also means all the Chiefs have to do is either kick a field goal or score a touchdown to win. Like I said before, the Chiefs over the last two years have scored in some form on a shade over 50 percent of their drives. What this does not account for is garbage time. With the game on the line, you would assume the Chiefs would be very aggressive throwing and moving the ball downfield. They have spent such a large portion of the past two years ahead, thus many of their drives involved trying the churn the clock as opposed to trying to score. When the score is tied, following a punt the past two years the Chiefs have scored on 72.7 percent of their drives, per pro-football-reference, a figure 11.9 percentage points better than the next best team. So by punting, the Chargers were facing overwhelming odds to win the game.
This brings me to my next point. By not going for it in this situation, all Lynn was thinking about was not losing the game in that moment. Going for it close to your own endzone and might seem bad at first blush. In that case you are almost guaranteeing a loss. But punting is not much better; given the opponent you are also giving yourself almost no chance to win but you avoid the optics of a potentially disastrous fourth down play. And I have not even considered what happens if you do convert fourth down. On fourth down plays with one yard to go in between your own 30 and 40 yard line, NFL teams have converted at a rate of 72.2 percent since 1999. A 72.2 percent chance of continuing the drive makes going for it much more appealing than simply punting the ball back to this Chiefs team, given their scoring prowess. Using the win probability calculator at pro-football-reference, the Chargers would have a 51.1 percent chance of winning the game if they converted. Using that same calculator, the Chargers win probability was just 38.1 when punting and 19.4 percent upon a failed fourth down. When you account for the swings in probability for winning the game by converting and failing to convert the fourth down, the break even conversion rate for the Chargers is just 41.1 percent, more than 30 percent lower than the odds of them actually converting. Not going for it was so obviously the wrong decision I am still shocked Lynn decided against doing so. Though the decision did not totally seal the Chargers' fate, it effectively did so. It is amazing in the year 2020 we still have coaches making nine figures still make these types of decisions because they are worried about the optics of failing a conversion. If the Chargers are on the outside looking in for the playoffs at the end of the season by just a game, this decision against a division rival will loom large on Lynn's conscience.
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