Why Is Strength of Schedule So Ridiculously Complicated???

brandon nealCorrespondent IJuly 24, 2009

AUSTIN, TX - OCTOBER 18:  Roy Miller #99 of the Texas Longhorns carries an American flag onto the field before the game against the Missouri Tigers on October 18, 2008 at Darrell K Royal-Texas Memorial Stadium in Austin, Texas.  Texas won 56-31.  (Photo by Brian Bahr/Getty Images)

Strength Of Schedule. Why do those three words spark such debate?

You seem to have two groups of people in this debate. You have your people who are all about the Out Of Conference Schedule. These are the people who post threads boasting about how there teams are nutting up by playing big out of conference games. Titles such as "Looking for trouble. Teams that schedule tough OOC teams" and what not. For some reason they also usually take the time to blast big time teams. inparticular SEC who are guilty of scheduling lack luster games generally at the begining of the season. While completley ignoring that its the over all strength of schedule is whats important. They also seem to forget that usually theres a reason they have to play tougher out of conference competition. That reason is either weak conference or weak over all strength of schedule.

Then You have your people who are all about Conference Schedule. Alot of SEC and Big12 fans fall into this catagory. These people feel that if your conference schedule is gonna line up up against top notch teams then thats good enough.

Now what you read was just a few of my opinions. Next Id like to give you some facts.

Strength of Schedule

Strength of Schedule (SOS) is a rating which applies to a teams schedule
where the stronger the opponents, the higher the SOS rating, or conversely,
the weaker the opponents, the lower the SOS rating. In order to tabulate
an SOS rating, the opponent's strength has to be evaluated. A measure of
an opponent's strength is its power rating or the record of its opponent and
their opponents. The higher the rating, the
stronger the team.

There are three methods that come to mind when doing an SOS rating.
The first method uses an average of all opponents PR's to arrive at the SOS.
A second method uses a weighted average of the PR's so that 'tougher games'
are not "diluted" by games against weaker teams. A third method uses the
last two components of the Rating Percentage Index Method. It employs the W-L
record of the opponents and the W-L record of the opponent's opponent. This
method employs the Ratings Percentage Index (PRI).

All three methods are demonstrated below with the advantages and disadvan-
tages for each illustrated. The results of all three methods are shown for:
(1) average, (2) weighted average and (3) RPI. We use the college
football schedule for the year 2001 through Oct 31,2001 and use the game results
of Oklahoma to derive the first and third calculations. Note that the results
vary based on the method.


Oklahoma has played 8 games (Power Ratings as of October 31 shown in

North Carolina  (71.61)
Air Force       (43.94)
North Texas     (46.95)
Kansas State    (70.70)
Texas           (82.47)
Kansas          (52.75)
Baylor          (44.53)
Nebraska        (84.16)

The three methods are:

(1) Average of the Opponent's Power Ratings

The average power rating would simply be the sum of all opponent power ratings
divided by the number of games played. If the game was against a team
outside division I, then the game would not be included in the SOS rating.
All games for Oklahoma were in Division I. Averaging the opponent's power
ratings we get.

  497.11 / 8    =  62.19

Advantages: Simple to understand and explain. Disadvantages: Does not
emphasize playing the best teams and penalizes for adding weaker teams or
requires computer ratings.

(2) Weighted Average of the Opponent's Power Ratings

If we want to give added weight to tougher games so that a team
that plays a strong team (PR = 75.) and a weak team (PR = 25.)
will have a higher rating than a team that plays two average
teams (PR = 50.).

So lets consider two cases:

Team A plays two games against average teams (PR = 50.), whereas
Team B plays two games against a tough team (PR = 80.) and a weak team
(PR = 20.). The average PR or average SOS of team A is (50. + 50.)/2. = 50..
The average of team B is (80. + 20.)/2. = 50.. So both teams have the
same SOS when averaging. But what if we want the team that plays a stronger
team (PR= 80.) and a weaker team (PR = 20.) to have a higher strength of
schedule because we want to emphasize the stronger opponent and not significantly
punish a team for playing a weaker opponent. Then, when we do the average we
do the exponential of the opponents power ratings using 2.5 as the exponent.

Team A's SOS = ((50./100.) ** 2.5 + (50./100.) ** 2.5) * 100.
             = (0.5**2.5) + 0.5**2.5) * 100.          = 35.35

Team B's SOS = ((80./100.) **2.5  + (20./100.) ** 2.5) * 100.
             = (0.8**2.5 + 0.2**2.5) * 100            = 59.03

So instead of getting 50. for both, we now get 35.35 and 59.03
which means player tougher opponents will yield a higher SOS.
This technique is called weighted averaging.

Advantages: Emphasizes playing the best team while not penalizing
for adding weaker teams. Disadvantages: Not simple to understand or
explain; requires computer ratings.

(3) RPI Method

The RPI Method is discussed at RPI and is based on
a teams record and its opponent's record and their opponent's records.

The 2nd and 3rd components, when added yield the Strength of Schedule. This
moethod is based on wins and losses and not goal or point margins or other
factors contained in the first two methods.

In summary, there is not a lot of difference between average and weighted
average but there are noticeable differences between the RPI
and the average/weighted average approaches. There are additional issues
such as: (1) Should only games played count in the sos or should all games
scheduled count? (2) Should games outside a division count?  (3) Should road
and home games count equally? and (4) Are point or goal margins important
as is the case with the averaging techniques and not the RPI technique?

Now is it just me or do you feel more stupid after reading that. Lets play word association. "What you just read"! Answer "Huh"??? Why is it that complicated?

Is it fair to say that Miami of Ohio is rated higher than say a texas or a Florida who are two teams that are gonna have multiple top 10 match ups along with multiple top 25 match ups. Or a team from the tiny conference and a tiny school who played a bunch of smaller teams with winning records?

Here's how I do it. Its so simple its crazy i guess. If your Ohio State and by the end of the season you have only played one top 25 team than it should reflect in your ranking. If at the end of the year your a Florida or a Texas and your over all schedule has you facing a couple top ten matchups and multiple top 25 match ups then your SOS should be higher and your ranking should reflect it. Simple as that.