Andy Reid’s Other Lead Foot

The latest from the sports data science guy at KC Sports Network, Joseph Hefner

This is the second article in a row I’m writing about an appendage of Andy Reid’s. Can’t say this is what I was expecting when BJ brought me on board with KCSN, but here we are.

Last week’s article covered how often Reid/the Chiefs win compared to Vegas expectations, and found that they win at the highest rate in the NFL. 

We also looked at whether they performed better or worse than Vegas point spread lines, regardless of winning. Do they eek out these victories, or do they dominate? We found out that while they do win these sorts of games, the games are closer than expected more often than other top contenders. 

Here’s a scatterplot that should serve as a bit of a refresh of last week's article. I’ve filtered it to just games with greater than 60% win probability (games where the team is a 3.5+ favorite) and to teams with 20 or more of these games.  The X axis (horizontal) is the overall cover percentage. The Y axis (vertical) is the overall win percentage. 

As you can see, the Chiefs win these games at a significantly higher rate than the next best team. However, the Chiefs also fail to cover more often than 13 of the 24 teams meeting the criteria. So it does seem as though the Chiefs make us hold our breath more than other fanbases do. 

Next, I wanted to take a look at how much of a game we spend holding our breath, so to speak. To calculate this, I looked at the pregame Vegas win probability, then calculated the percentage of plays where the in-game win probability was higher than the pre-game win probability, which updates after every play.

As an example, in last week's Houston game, the Chiefs spent 3 total snaps at a higher win probability than the pregame win probability number. That makes sense, because it was an awful game to experience, and I did not enjoy it. The Chiefs had a 1% win probability over starting odds in that game. 

The Chiefs spend more time than any other team with a win probability that is better than at the start of the game. The Chiefs are best in the league when they are mid underdogs. They are second in the league when the pregame starting win probability is between 61-80%. 

However, when we look at just that 81-100% bucket, they drop to eleventh. Some of that is due to small sample sizes of some teams ahead of them, but not a lot. Once again, we see that the Chiefs don’t step on the gas against very bad teams. 

One thing that needs to be pointed out at this point is that the Chiefs have a lot more games and snaps in the 81-100% pregame win probability bucket than the rest of the NFL. The Chiefs have 4 more games (20) and  692 more snaps (3,266) than the next team, and 7 games and 1,213 snaps more than the 5th team. They spend A LOT of time in this bucket. 

The last thing I want to take a look at before putting this topic to bed is what happens in the fourth quarter. This is the point in these games where we’d all like to be comfortable, just watching in the background because we’ve got the game all sewn up. It’s also the most stressful quarter when we are left wondering if we’d pull it out again this week. 

Here’s the same chart as above, filtered down to just the 81-100% group, and separated out by quarter. Hopefully this helps you get a feel for the general game flow. Some teams don’t have any games in the past 5 years with a starting win probability higher than 80%, so they don’t show up in this table. 

The Chiefs are 13th overall in this graphic, out of just 25 teams. Here are their rankings for each quarter: 

First Quarter: 7th (tied)

Second Quarter: 17th

Third Quarter: 11th

Fourth Quarter: 12th (tied)

That certainly makes for some games that are less fun to watch than we all want them to be. Much less domination than we’d have a right to expect. Nevertheless, even if the ranking is not as good as some of the other teams, 73% of the fourth quarter snaps in our games have a win probability higher than we started with. That’s still pretty nice. 

I’d also like to point out that we’re not alone down there. Buffalo is 12th. Similar ranks in each quarter as us, too. Much better in the second quarter, much worse in the third. They’re a team I often hear people say “puts the hammer down” on bad teams, but the data definitely doesn’t back that up over the past 5 years. 

We can argue about who is responsible for our underperforming against bad teams, and I think there’s a lot of questions there. Does Andy just not call the good plays? Do we just play vanilla offense and defense and trust our talent over scheme? Do we just play sloppy? More drops or turnovers than normal? 

It’s really difficult with publicly available data to separate out what percentage of a team's performance is the team vs the coach vs the opponent. I do believe issues that span multiple years should be placed primarily on the coaches, though. It’s their job to get players focused and ready for games, even layups.

On the other hand, we win these games. 20 games in the past 5 years. 19 wins, 1 loss. Whether it’s Andy Reid, or the Chiefs, or the Spirit of Mahomes, we win these games. They may not look as pretty as we want, but we do end up with the win. 

So the next time we find ourselves playing a team like the Texans or Denver, and the game is feeling tighter than it should, I’m just gonna try to take a mental step back and breathe a little. Andy’s got this. The Chiefs got this. Patrick’s got this. We got this.