Exclusive: Here’s a look at unofficial updated Strength Index numbers for all NJ Football teams following Week Zero play

With the shutdown of Gridiron New Jersey over the summer – and the job of calculating the NJSIAA’s complication playoff formula moving to NJ.com, Central Jersey Sports Radio will continue to run its own unofficial numbers all year, and that includes the Strength Index calculations, which are critical to figuring out a team’s OSI (Opponent Strength Index), which is 60 percent of the playoff formula.

Unlike Gridiron, at least for now, it doesn’t appear NJ.com will be publishing the Strength Index numbers on a weekly basis. While the playoff standings are expected to debut after a couple of weeks – most likely after Week 2 play, since early season standings are often misleading when some teams have only played one game – Gridiron had always updated each team’s page with their current SI value. We would run our own numbers to compare with Gridiron the first few weeks, but no such mechanism currently exists.

So, we’ve run our own numbers, and are publishing today the season’s first unofficial updated Strength Index values.

We’re confident in about 95% of our numbers, but a little less about the rest. Why? Because out-of-state opponents are tricky. We’ll get to that in a bit.

Each week, SI values change based on the final score and the rating of the two teams that played. Here’s an example. SI goes up or down depending on how a team did compared to the difference between the two teams. If Team A (80 SI) plays Team B (60 SI) and Team A wins by 20, there’s no change. If Team A wins by 10, they underperformed by 10 points, and Team B overperformed by 10 points. Team B increases by 2 points to become a 62, and Team A drops to a 78. Team A then gets the full value of Team B for its OSI (62) while Team B gets half the value of Team A (39).

In a real life example this week, let’s take Piscataway and East Orange, a game played on Saturday. Piscataway had a preseason SI or 68.34, and East Orange had a 66.91 SI value. Piscataway is considered 1.43 points stronger, but won the game 26-20, a six-point win. In that sense, the Chiefs overperformed, and would rise, while the Jaguars would go down. By how much?

Piscataway “beat” the expected result by 4.57 points. The formula says “divide by 5,” so we get 0.91 out of that. Add that to Piscataway’s number and we get 69.25. Subtract that from East Orange and we get 66 even. Those are the new SI numbers.

When it comes to SI, Piscataway won, so they get all 66 points. Since East Orange lost, they get half of Piscataway’s 69.25, or 34.63 OSI points.

Here are Central Jersey Sports Radio’s UNOFFICIAL Strength Index values after Week Zero play:

Now, back to the out-of-state opponent issue.

Some of the teams who played non-NJ opponents in Week Zero may be slightly skewed. The issue is, we need to come up with an SI value for the out-of-state team, but they are not part of the New Jersey formula.

NJSIAA rules are this: Find the out-of-state team’s rating on MaxPreps. Then find the two closest New Jersey teams to that rating number (the first one above and the first one below). Then we take the SI of those two teams and average them.

But MaxPreps ratings are sometimes updated multiple times a week, and also depend on other games being played, whereas SI is only dependent on the two teams that play a game, and OSI can go up or down in a given week, depending on how past opponents play. MaxPreps essentially rolls that all into one.

For CJSR, we found the SI values of the out-of-state opponents Big Central teams play this year (just Phillipsburg – which has three – South Hunterdon and St. Thomas Aquinas) a few weeks ago when we did our “projections” for the playoffs, because we needed the SI of all opponents. However, we neglected to to that for the entire state, and there were 17 other teams that played out-of-state opponents this week.

And we can’t use the MaxPreps ratings as of today, because they have already been updated based on Week Zero results. So we had to reconstruct what we think are the correct numbers based on Google searches. If the adjusted SI numbers for New Jersey schools are off, they are not by much.

NJ.com should be calculating all of this in the background for Week Zero, so we trust they did this research. (If not, it is tricky to go back and fix it, for the reasons we mentioned above, but it needs to be done; if the SI numbers are off after Week Zero, that affects Week 1 games, then the number of teams wrong grows exponentially.)

That said, here’s a real life example. Rumson-Fair Haven played Tottenville (NY) from Staten Island this weekend. We determined that Tottenville’s preseason MaxPreps rating was 61.08. So, we then looked at who the closest New Jersey schools were. St. Joseph-Hammonton was the closest above at 64.4, while Seneca has a 60.82 MaxPreps rating, the closest below. Now we find their SI values (57.24 for St. Joe’s and 74.98 for Seneca) and average: we get 66.11. That’s the SI we use for Tottenville in the game vs. Rumson, which had a 73.05 SI coming in. Since the Bulldogs “underpeformed” in the game – winning by one when they were “expected” to win by 6.94. Rumson, as a result, saw its SI fall to 71.86 this week.

One other note… the formulas are not the same, and we believe some other option should be considered in the future. Look back at how we found the MaxPreps ratings. St. Joe’s-Hammonton was almost four points higher in the MaxPreps numbers, but Seneca was more than 17 points higher in the SI value. So, it’s not an entirely accurate way to determine out-of-state SI, but for now, it’s all we have.