Seeing the Future, Part Two: Predicting how the 2017 season will go for the Steelers Ben Roethlisberger

With all due respect and apologies to Terry Bradshaw, Ben Roethlisberger is the best quarterback to have played in Black & Gold. Statistically, he’s in a league of his own.

That’s the type of statement that riles up the old and the young amongst Steeler Nation. That’s because comparing the two eras is difficult, if not impossible. So, it’s safe to say arguing either way ultimately boils down to hyperbole, with dogmatic adherents on both sides.

The absolute in the argument is that Roethlisberger owns most of the top statistical seasons in Steelers history. And there is little reason to think it won’t continue in 2017, especially with receiver Martavis Bryant, an exceedingly potent downfield threat, back in the fold.

But the question is, how good will it be? It’s not possible to know the answer with any certainty because there are too many variables, but there’s nothing wrong with trying to predict a few key numbers based on past performances.

In the first part of this series, we looked at how we can apply linear regression to make these predictions.

Total Yards

To paraphrase Apollo 13 pilot Jack Swigert: Houston, we have a problem.

The problem: Roethlisberger had a statistically down year in 2016, following up his career-best year.

Solution: we “weight” 2016’s numbers to bring it more in line with 2014 and 2015. Of course, that’s a slippery slope, because we basically have to make up the method. Again, there are simply too many variables to apply any sort of scientific method without crunching far more numbers that I care to for a simple prediction. Instead, we’ll take a few basic ideas to add yards to Roethlisberger’s 2016 numbers.

Now, the biggest variable here the absence of Martavis Bryant. His presence brought both Roethlisberger’s and number-one receiver Antonio Brown’s numbers up, due to the need to roll coverage toward Bryant. In 2016, there was no real threat in the number-two slot once Sammie Coates injured his hand.

So, to create a mostly fair system for adjusting Roethlisberger’s numbers, let’s simply figure the difference between Bryant’s yards in 2015 and those of Eli Rogers, who was the Steelers’ statistical number two, in 2016. After normalizing to 16 games, Bryant would have had 1,112 yards. Subtracting Rogers’ 731 normalized yards, we end up with 381 additional yards that Roethlisberger had with Bryant that he didn’t have without a true number two.

But, there is one more adjustment we need to consider. We could find a way to adjust for every receiver on the roster, but the two biggest impacts felt by the absence of a true number-two receiver are the lost yards for the number two, himself, and the lost yardage for the number-one receiver — Brown — because defenses were able to commit more coverage to Brown than they would be able to do with Bryant as the team’s number two.

However, we can’t legitimately say the entire drop in Brown’s numbers were due to the absence of Bryant. So, to be fair, let’s assume just half of the decline resulted from that cause. Brown’s normalized yards in 2016 come to 1,370, a decline of 464 yards. Adding half of that to Roethlisberger’s normalized yardage, along with the adjustment for Bryant, bumps his normalized yards up from 4,365 to 4,978.

Based on that, when applying linear regression to find the trend line, we find that Roethlisberger is theoretically on pace for a whopping 5,247 yards if he plays every snap. Taking standard error (in this case, 525 yards) into account, a 16-game season would yield anywhere from a realiztic 4,722 yards to an outrageous 5,772 yards. That averages to 360.8 yards per game. It’s a hard number to fathom, especially given that it’s a 10 percent increase over his career-best 328.2 yards per game, set in 2015 when he only played in 12 games -- missing contests against defensive stalwarts Baltimore and Kansas City.

Touchdowns

Believe it or not, we don’t need to make any real adjustment to touchdowns for the absence of Martavis Bryant. As far as scoring touchdowns in the red zone, the Steelers were a mere three percent better in 2015 than in 2016. And they actually nearly doubled their number of scoring plays from outside the red zone, from eight in 2015 to 15 in 2016. So, from a scoring perspective, Bryant’s absence had no appreciable, negative impact on scoring. If he played all 16 games, Roethlisberger would throw 32 touchdowns, tying his career best.

Interceptions

Just like with touchdowns, there is really no need to make any adjustments for interceptions due to the loss of Bryant. In a 16-game season, Roethlisberger would throw 13 interceptions.

Completions and Attempts

In a 16-game season, Roethlisberger would complete 423 of 636 attempts, tying his fourth-best career completion percentage of 66.4, also done in his rookie year.

Games

One other key number, though, will affect all of Roethlisberger’s other numbers: he is likely to miss time for injury, as he has done in eight of 13 seasons. We do need to normalize the data to account for missing games for reasons other than injury — specifically, this most affects his rookie season and 2010, when he missed four games due to suspension that has a chance of recurring that approaches zero. As it turns out, though, it doesn’t matter: the normalization doesn’t shift the needle enough to change the forecast. Roethlisberger is likely to play 14 games in 2017.

Wrapping up

Based on all of this, and accounting for two missed games, my final predictions for Roethlisberger are:

Yards: 4,517
Y/G: 322.6
Completions: 370
Y/C: 12.2
Attempts: 557
Y/A: 8.1
Completion %: 66.4
Touchdowns: 28
Interceptions: 11