In the meantime, we're putting in a plug for one of our favorite sites, the good folks over at pro-football-reference.com. (Here we state that no one here is affiliated with or has any sort of financial relationship with that site, its ownership or management, or anything else. We're just fans.) It's a wonderful compendium of all things related to pro football, and if we've had our disagreements with their editorial staff from time to time (since when are the winners of the 1967 AFL and 1968-1969 NFL Championships relegated to runner-up status?), it's a place we regularly visit and support, and we encourage you all to do the same.
One statistic of great interest to us that was not developed at or by anyone at p-f-r, but one that is popularized there, is the "Simple Rating System" or SRS for short. Basically, the SRS combines a team's margin of victory with its strength of schedule to estimate the team's true strength, which may be camouflaged by its won-lost record. One claimed use of the SRS may be as a practical point spread, illustrating the difference between two given teams, though home-field advantage will also play a part.
The methods used to develop the SRS are explained in full on the p-f-r website and will not be repeated here. Essentially each team's cumulative margin-of-victory (MOV) is calculated, then measured against the MOV for all other teams, with a plus-or-minus result obtaining. MOV is a constant; strength-of-schedule (SOS) is a variable that changes every time a MOV comparison is made. The comparison process, therefore, must be repeated for each team-game over the length of the schedule until the product (SRS) itself remains constant. Something like this is going to require an Excel spreadsheet or similar program. For lazy people like us, we just go to the site and review the year-by-year standings to see where SRS diverges from won-lost record.
In our opinion, the stat has limited value as a point-spread comparator. Where it will deliver its highest and best value is in looking at teams over the course of a season or several seasons. For instance, dominant teams, great teams, do tend to win a lot of games by lopsided margins: regular blowout wins are a mark of excellence. By contrast, those "Cardiac" teams that win games by the skin of their teeth week after week are wonderful entertainment for the fans, but those teams do not tend to dominate, especially in the postseason. There are exceptions, of course. But generally, a team with the highest SRS over the course of a full season is, most of the time, the best team in the league.
Whether that team is the best bet to win the Super Bowl-- well, there's where the fun begins.
Certainly there are limitations to this method. For instance, how do we define a blowout? At what point is the MOV superfluous in a blowout? Is a 50-point win really more valuable than a 28-point win? This method says it is; the higher the margin the higher the SRS will be. Is one 30-point win more valuable than two 10-point losses? Few fans, players, or coaches would say it is, but SRS will count it so. And over the course of the season, perhaps such a trend does prove a more valuable indicator of strength than does the won-lost record. The NFL, after all, counts both MOV and SOS in its ultra-complicated playoff tie-breaker schemes.
We're interested in using SRS to see if we can answer questions such as these:
- Were the teams we remember as the league's best during the regular season, but who tanked in the playoffs-- the 1967 Rams, the 1980 Falcons, the 1995 Chiefs are all examples-- really that good?
- How do the great 49er teams, such as the Walsh/Seifert squad which won 18 consecutive road games from 1988-1990, measure up by this method? Which is the most powerful 49er team of all time according to SRS?
- What's the strongest team ever, measured by SRS? Did that team win a championship? Which teams with modest, or even lousy, SRS numbers won it all?
- Is it possible to quantify a predictable relationship between SRS and W-L record, perhaps over multiple seasons?
Over time we'll explore each of these questions and share the results with you. It could take months or years, or it could be complete by the end of this season if our beloved-but-struggling Niners don't shape up quick.