The Playoff Foles-om Prison Blues

What version of Foles will show up next weekend?

Let’s hop in a time machine. I’ll tell you a story about a young Eagles quarterback who led his team against the Raiders. In this particular instance, the Eagles were bound for the playoffs and the Raiders weren’t, though neither team was sure of their fate at the time. Philadelphia, a one point underdog to the hometown Raiders, proceeded to run wild over the Raiders secondary. The Philadelphia QB threw only 28 passes, completing almost 80% of them for 406 yards and a record-tying 7 TDs, yielding a perfect 158.3 quarterback rating — a rating that only nine other quarterbacks have managed since 2000 while throwing at least 25 passes. The quarterback was Nick Foles, and the date was November 3, 2013.

Just over four years later, Foles would face off against the Raiders again but with markedly different results. Two weeks ago, Nick Foles squeaked by the Raiders 32nd-ranked secondary, completing only 50% of his 38 passes for 163 yards, one touchdown, one interception (he was lucky not to throw more), and a 59.4 quarterback rating. Yikes.

Next Saturday, Nick Foles and Co. will suit up to face off against the Falcons, Panthers, or Saints in the divisional round of the playoffs. Riding the number one seed through the wild card weekend gives us a chance to reflect on what the Eagles’ fate is next weekend. Put more simply, which version of Nick Foles will show up for the game?

While I was watching the Eagles game against Dallas, it occurred to me that Foles might just be really bad in cold weather games. This might explain his recent performances at home against Dallas and Oakland. To figure that out, I looked at every game of Nick Foles’ career in which a) he played outside and b) threw at least ten passes. I correlated his passer rating with the kickoff game temperature to see if there were any patterns there, and then I tweeted about it (chart replicated below, with corrected axis labels).

The takeaway here? There’s no statistically significant correlation between the ambient temperature and Nick Foles’ performance. His worst passer rating came on a 70+ degree day; his fifth-best passer rating came in the 30s. Below is another chart showing Foles’ historical performance, based on passer rating (this chart eliminates games in which he threw less than ten passes).

What strikes you right off the bat in this chart is how high the variance is between Nick Foles’ career starts. His career average is a respectable 88.1 passer rating, but that number is largely boosted by his impressive 2013 campaign. Since the end of 2013, his rating is 77.7. That’s a big dropoff from Wentz, whose 101.9 passer rating this year was good for fourth in the NFL. And indeed, this year Foles’ passer rating is right in line with his post-2013 average, and at 79.5 he sits at 31st in the NFL, just ahead of Marcus Mariota and Mitchell Trubisky. But given this chart, another conclusion we can draw is that average passer rating is certainly not the best way to evaluate Foles’ future performance.

Streaky players tend to have good stretches and bad stretches. Not Foles: he tends to have a good game or two, then a bad game or two, and then rebound to repeat the cycle. In his career, I only found one instance in a season when he had more than two consecutive games in which his passer rating declined. That happened in November and December of 2015, arguably the roughest stretch of Foles’ career (passer ratings of 68.7, 53, 49.9, and 43.3 respectively). Apart from that, Foles has shown a remarkable if perplexing ability to turn things around — hence why, on the second chart above, you see dramatic rebounds from poor performances.

I’ve said before on my podcast that I think Nick Foles has a lower floor than most starters but a higher ceiling than any other backup. The chart above corroborates that, and if history is any guide, we’re due for a rebound performance in the playoffs. But if we make it to the NFC championship, don’t hold out for a miracle. If Nick Foles peaks next week, he’ll likely dip again after that.

Would love to hear what you all think! Did I miss something? Be sure to let me know!

Many thanks to Pro-Football-Reference’s Play Index for making this data available. If you want to see my spreadsheet work, have at it.

Follow Zac on Twitter or Medium, and listen to 3rd String Podcast.