Offseason Plan - Part 3 - Positional Value

Kyle Snow is back with another guest post. This time around, he’s taking a look at a few 49ers players and their positional value.

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To determine the positional value, I plotted the average level of play (as indicated by PFF) against the regular-season win % and factored in the strength-of-schedule. I only did this for the 2020 season, and there are so many limits to this experiment that I won’t list them all.

The premise is simple though, what makes a good team good? To define “good,” I went with regular-season win % because football is such a high variance sport. I didn’t want to include playoff games, where a team could get unlucky and lose in the first round. I also factored in strength-of-schedule, so beating the Chiefs would be worth more than beating the Jets.

I’m not going to go into any fancy statistics unless you ask me to. I’ll just post the plots and let you look at the raw data to draw your own conclusion. The best fit and equation line is straight from Excel, so you can easily replicate the results.

Let’s get started! If you were to guess the most valuable position on the field, you’d probably guess quarterback, and you’d be right…sort of. We will come back to this. Look at the chart below. Even with Deshaun Watson (circled), the better the quarterback play, the more successful the team. This isn’t the strongest correlation that I found, but QB is talking about just one player, whereas another position such as WR might be talking about 5 players.

So, what’s the second most important position on the field? Well, this article is starting very similar to The Blind Side, so you might be thinking Tackle. Have a look:

The data doesn’t look overly correlated here, but the line of best fit shows the second-highest slope. There isn’t a huge range in Tackle play either. The best team was just over 80, PFF, whereas the worst was a little under 60. I circled Pittsburg here as their Tackle play was so bad compared to their rate of success; it seems like an outlier.

So, if Tackle is second, what’s first? If you’ve been listening to Kyle Shannon and John Lynch since 2017, you probably heard the notion that the Defensive line has to dominate the line of scrimmage for a team to win. You might also remember the high draft picks (Thomas, Bosa, Kinlaw) and big-name free agents (Ford) to bolster the positions. Let’s take a look below.

It looks like Edge Defender doesn’t have any correlation to team success at all, whereas Interior D-Line has some correlation, but not as strong as Tackle.

So, what is it? Without further ado, the most important position in the NFL 2020 season was:

Even for a beginner statistician like me, it’s hard to argue. It looks pretty clear that the better your cornerbacks played, the more success the team had. I am well aware that you are going to tell me that getting pressure on the quarterback is highly linked to the play of the cornerbacks, but I’m just reporting what my numbers tell me.

Now let’s evaluate these conclusions from what we saw in the field. Luckily for us, the Niner’s season aligns with these theories very well. Last year, we had one of the best defensive lines in the history of the sport. The defense was so good that Solomon Thomas couldn’t crack the starting lineup. Then we lost Deforest Buckner in the offseason and Nick Bosa and Thomas just 2 games into the season. Naturally, you would expect a huge drop off after losing two elite players in what Lynch/Shannon think are the most important positions on the field, right?

There was a drop-off, but it wasn’t as drastic as you’d expect. There are a thousand ways to grade a defense, but we allowed about 4500 yards in 2019 (2^nd in the league) and 5000 in 2020 (5^th in the league). You might not be surprised to know that offensive turnovers probably accounted for at least some of this difference.

Even on a smaller scale, look at two games against the same team in the season and look at the results. On September 13^th, our defense could not stop the Cardinals. The stats might not show it, besides the 29 first downs allowed, but it was hard to watch. Against the same team in December, we shut that offense down. What was the difference? Nick Bosa and Jimmy Garoppolo were available on September 13^th, so wouldn’t it make sense that we would have been better with them in the lineup?

If you watched both games, you know exactly what the difference was. In September, DeAndre Hopkins torched us for 151 yards, whereas in December, Jason Verrett could limit Hopkins to only 48 yards. The cornerback play was more important than the edge defender play.

As this is my third article, and I haven’t made a recommendation yet, you’re probably looking for an unpopular take by now, and the wait is over. First, let’s take a look at one more position, linebacker.

That’s right; it is almost impossible to draw any correlation between linebacker and the overall team performance. If you did grasp at straws and try to take something from this chart, you would find a negative correlation between LB play and team success. Now, I don’t actually think that having good linebackers is a disadvantage, but we are playing in the salary cap era. If you pay your linebackers, you might not have enough cash for other, more important positions.

Keep in mind that this data is only based on one year. Team success is likely based on at least ten other factors besides how good the players are (like luck or coaching), and not all of this data is actually statistically significant.

However, based on the data presented here, the Niners' worst move could make this offseason give a massive contract to a certain linebacker and let all of their star cornerbacks leave. All year, I think I’ve heard more about “All-Pro Freddy” than any other player. Aaron Rodgers dubbed him the best linebacker in football, and I agree. He’s awesome. But what we can’t do, is make him the highest-paid linebacker in NFL history while we let Verret, Sherman, and K. Williams walk out the door. Even more generally, we can’t continue to invest in-low value positions.

Thanks so much for reading. I appreciate all of your comments and feedback. Hit me up on Twitter, @goldrushkdawg, and for a limited time, you have the opportunity to be my first follower.