I’ve added a little more sophistication to my strength of schedule model for the new season.

More people have come to this site in search of strength of schedule information than for anything else over the past year.

So I’ve decided to make strength of schedule a permanent part of the Football Frontier.

My model takes the ratings of each team played, and modifies them by 15% for neutral-site games and 30% for road games. Analysis shows this is the proper modification, based solely on conference play over the past two seasons.

Here is the final strength of schedule chart for 2007:

2007 College Football Strength of Schedule

The SoV columns refer to Strength of Victory, which is what the NFL uses to break ties for playoff positions. The idea behind SoV is that it measures what you’ve accomplished, rather than what you’ve attempted.

I prefer SoS (Strength of Schedule) for college football because schedules are so vastly different in the college game, while in the pro game, the league tries to make all schedules roughly equal.

Here’s this season’s college football schedule strength chart:

2008 College Football Strength of Schedule

Note that the Pac-10, as usual, leads the way. That’s because they play nine conference games, while most other conferences play eight. This eliminates one mediocre non-conference opponent. Keep in mind the SEC, ACC and Big XII all have conference championship games, which improves the schedule strength of the division winners. Georgia, therefore, might well wind up playing the hardest schedule in the entire country.

The 2008 season is just two weeks away, believe it or not. All across the country, students from hundreds of college are strapping on pads and helmets and trying to figure out how to translate Xs and Os from playbooks into action.

I have my season preview at the ready, and I believe the Georgia Bulldogs are set to continue right where they left off last season. With Matthew Stafford and Knowshon Moreno leading the way, Georgia will score a lot of points. And led by an experienced secondary, the Bulldog defense will be hard to beat as well.

Football Frontier 2008 Pre-Season Ratings

Rounding out the top five are Ohio State, Southern California, Florida and Louisiana State.

There’s still time to enter our Sixth Annual NFL Draft Contest, which takes place on Saturday, April 26.

To enter, just fill out the form and submit your guesses for the 31 picks made during the first round of this year’s amateur draft.

If you entered early and did not have Michigan offensive tackle Jake Long as your first pick, please feel free to go ahead and enter again. We’ll just delete your original entry.

To wrap up this series, I’m presenting the list of discretionary calls made, by referee.

This includes all the discretionary calls not attributed to the umpire in part four: defensive and offensive pass interference, illegal contact, roughing the passer and intentional grounding.

Of these calls, the referee is only directly responsible for the latter two. Based on zone, the five officials (field judge, back judge, side judge, line judge and head linesman) who ring the defense study the individual receiver/defender matchups and throw the interference and contact flags.

Since separating out each official’s calls is impossible based on common play-by-play data, I assigned these calls to the referee, who is the crew chief. Generally, crews work together for the entire season.

Last season, this subset of calls accounted for only 1.65 penalties per game (13 percent of all penalties). When you think of the impact of interference and contact calls alone, that’s a surprisingly low number.

In fact, including the line calls attributed to the umpires, discretionary calls account for 3.73 penalties per game. But as I’ve written more than once in this series, these are the calls that dictate to coaches and players what’s allowed within the rules. These are the calls that fans complain about on talk radio Monday afternoon. These are the calls that have coaches fuming in post-game conferences, trying to walk the line between expressing frustration and getting fined.

While this list is not a true indication of how a referee controls the game, it is relevant information.

Averages were weighted by the average number of those calls made during each season.

Referee	Calls per Game	Compared to Average
Gene Steratore	2.32	+31.2%
Terry McAulay	2.55	+23.3%
Tony Corrente	2.41	+17.6%
John Parry***	1.93	+17.0%
Ed Hochuli	2.29	+11.3%
Ron Winter	2.21	+7.2%
Tom White*	2.38	+6.9%
Mike Carey	2.13	+3.8%
Larry Nemmers**	2.10	+0.9%
Jeff Triplette	2.10	+0.3%
Scott Green	2.06	-0.8%
Gerry Austin**	2.01	-1.1%
Walt Anderson	2.01	-1.3%
Bernie Kukar*	2.13	-4.9%
Walt Coleman	1.90	-8.3%
Bill Vinovich*	1.98	-9.3%
Jerome Boger	1.60	-10.2%
Johnny Grier*	2.06	-11.1%
William F. Carollo	1.74	-16.4%
Peter Morelli	1.69	-17.3%
Ron Blum*	1.70	-17.3%
Bill Leavy	1.71	-17.9%
Bob McElwee*	1.67	-18.6%
Dick Hantak*	1.38	-32.8%

* - retired before last season
** - retiring before 2008 season
*** - 2007 was first season as umpire

In the future, I’d like to focus more deeply on pass interference calls, since these are often the most controversial penalties. To do so, I need to find a way to isolate the referees actually making these calls.

With six seasons of data, I don’t have enough material for a focused study. There are only 0.80 defensive pass interference calls made per game in the NFL. With five different officials throwing these flags, all reporting to the crew chief, this would be a fairly serious undertaking.

I hope Football Frontier readers have enjoyed these reports, and are looking forward to the 2008 season, when the Frontier will have more frequent new material.

There’s a significant variation in how each officiating crew approaches discretionary penalty calling.

Since these penalties are based more on rule interpretations than concrete “yes or no” violations, each call has implications far beyond the one play it affects. Coaches and players often have to make immediate or long-term adjustments, possibly even determining strategy based on which crew is assigned to the game.

When penalty calls dropped from 16.2 to 13.1 from 2005 to 2006, a decrease of 19.0%, the small subset of key discretionary penalties, which made up 36.3% of all calls in 2005, dropped from 5.9 per game to 4.3 per game, a decrease of 27.7%.

The drop in discretionary calls made up 52.9% of the entire decrease in penalties.
Even more convincing: when penalty calls dropped another 3.3% from 2006 to 2007, discretionary calls dropped 12.6%. There was actually an increase in penalty calls outside the subset - the discretionary call drop made up 122.3% of the entire decrease.

Umpires are responsible for most penalty calls involving linemen. So I separated out the discretionary calls they usually make - offensive and defensive holding, and illegal use of hands - and studied the number of calls each individual made over the last six years.

Averages were weighted by the average number of those calls made during each season.

Umpire	Calls per Game	Compared to Average
Carl Paganelli	4.03	+39.0%
Bob Wagner*	3.55	+28.9%
Roy Ellison	3.30	+21.9%
Bruce Stritesky**	2.43	+9.5%
Ed Coukart*	3.43	+9.1%
Undrey Wash	3.12	+8.5%
Garth DeFelice	2.97	+4.1%
Scott Dawson	2.93	+3.5%
Dan Ferrell	2.88	+3.5%
Butch Hannah	2.68	+3.5%
Chad Brown	2.78	+2.4%
Darrell Jenkins	2.81	-0.6%
Jim Quirk	2.71	-1.4%
Steve Wilson	2.67	-2.3%
Brian Balliet*	2.84	-3.1%
Carl Madsen	2.70	-4.4%
Tony Michalek	2.48	-9.8%
Ruben Fowler**	1.96	-11.6%
Bill Schuster	2.45	-15.3%
Richard Hall	2.25	-20.8%
Jeff Rice	2.11	-28.4%
Jim Duke*	1.87	-32.1%

* - retired before last season
** - 2006 was first season as umpire

Since referees are crew chiefs, they do have significant control over the calls made during their games. So I also looked at the breakdown of these line calls for each referee.

By and large, officiating crews stick together for an entire season. But crews are often switched around during the off-season.

I found that the standard deviation from average was 16.8 for umpires and 14.8 for referees. So umpires have more effect on the number of line calls made, but referees clearly have impact.

As an example, umpire Roy Ellison calls as many holding penalties as anyone. He has been paired with Ron Winter, among the penalty-calling leaders, the last two seasons. In 2005, he was paired with Gerry Austin, who calls less penalties than any referee. Ellison was close to the league average in discretionary line calls in 2005.

You know the drill by now. The crowd roars as the visiting quarterback sets up under center. Players look uncomfortable as they struggle to hear the signals. A guard jumps too early, resulting in a five-yard penalty against the offense.

The crowd gets even louder as the announcers celebrate their contribution.

There’s no doubt visiting teams are called for more false start penalties than home teams. Last year, that edge was 1.56 per game to 1.30. Over the last six seasons, the visitors were called for 1.63 false starts per game to 1.37 for their hosts.

Credit the fans, on average, for an extra five yards every two home games. Maybe not as much as the announcers would have you believe, but significant.

Since the overall penalty numbers are about even, however, that brings up an interesting question. Do officials compensate, overtly or subconsciously, for this crowd advantage?

In most cases, a penalty is a penalty. But when looking at the small set of discretionary calls, which encompass about 33% of all penalties, there’s opportunity to counter a crowd that may be perceived to alter the delicate balance between the teams.

The following chart shows the number of calls that went against home teams and visiting teams over the last six seasons, splitting out false starts and key discretionary calls.

For reference, false starts make up about 21% of all penalties, defensive pass interference about 6%, defensive holding about 5% and offensive holding about 18%.

Year	Visitors	Home	Pct.	FSt.	DPInt.	DHold.	OHold.
2002	7.16	7.61	48.5	51.5	43.6	44.2	49.0
2003	7.29	7.51	49.2	57.3	43.5	37.2	45.0
2004	8.30	7.67	52.0	57.0	45.0	50.5	48.4
2005	8.04	8.17	49.6	53.3	41.2	46.6	48.2
2006	6.71	6.42	51.1	54.6	50.8	47.3	50.0
2007	6.38	6.31	50.3	54.5	44.8	53.9	44.0
Overall	7.31	7.28	50.1	54.7	44.6	46.1	47.5

Visitors = Average number of penalty calls against visiting teams, per game.
Home = Average number of penalty calls against home teams, per game.
Pct = Percentage of total penalty calls against visiting teams.
FSt = Percentage of False Start calls against visiting teams.
DPint = Percentage of Defensive Pass Interference calls against visiting teams.
DHold = Percentage of Defensive Holding calls against visiting teams.
OHold = Percentage of Offensive Holding calls against visiting teams.

Looking at those penalty calls, the answer was found in offensive holding in 2007. The home team was called for 1.23 holds per game while the visiting team was called for only 0.97 holds. That made up for the false start chasm. It was a league-wide change. Remarkably, 15 of the 17 umpires in the NFL called the home team for holding more often.

In 2006, however, the false start advantage went uncompensated, and visiting teams were penalized slightly more frequently than home teams.

In 2005, visiting teams and home teams were penalized at about the same rate, with the false start compensation spread out over several types of penalty calls. Most notably, almost 59% of all defensive pass interference calls in 2005 went against the home team - only three of the 17 crews called more pass interference against the visitors.

The numbers were startling taken as a whole. Over the six-year period, despite 438 more false starts against visiting teams, they were only penalized 48 more times than home teams. That’s 390 subconscious or overt make-up calls.

While there were variations, year to year, in the three discretionary calls studied above, the home team was flagged 425 times more than the visiting team. Now that’s only about one flag every four games, but it’s a real factor.

Most notable was the spread in defensive pass interference calls. Only in 2006 did visiting teams receive more than 45% of those flags. And, of the 24 referees who led crews over the last six years, only three have called more defensive pass interference against visiting teams during that span.

Those three crew chiefs: Gene Steratore (58.3%) who has only been a referee for two seasons, Tony Corrente (55.3%) and Ron Winter (50.7%). Of the other 21 crew chiefs, eight flagged visiting teams for less than 40% of all defensive pass interference calls. Of current referees with at least six years of crew-leading experience, that includes Terry McAulay (39.2%), the retiring Gerry Austin (38.0%) and Walt Coleman (37.1%).

Is there anything strange going on in those NFL officiating rooms? Hard to tell. The numbers are very odd, and suggest officials may be using discretionary calls to partially mitigate the home-field advantage.

Before coming to any serious conclusions, however, this topic warrants more study.

The easiest way to look at an officiating crew is by simply counting the number of penalties it calls.

The following chart shows every officiating crew that has worked over the last six years, ranked by how many penalties it calls related to the league average. Since some crews worked only in different years, the average is adjusted to the league average for each year the crew worked.

I’ve also included a split of calls against visiting teams and against home teams.

Referee	Calls per Game	Average	Visitors	Home	Difference
Johnny Grier*	17.17	+10.9%	8.61	8.56	+0.3%
Ron Winter	15.90	+9.5%	7.91	7.99	-0.5%
Jerome Boger	14.10	+9.2%	7.27	6.83	+3.1%
Larry Nemmers**	15.79	+7.7%	7.82	7.97	-0.9%
Terry McAulay	15.54	+6.8%	7.87	7.67	+1.3%
Ed Hochuli	15.42	+5.9%	7.71	7.70	+0.1%
John Parry***	13.20	+4.0%	6.33	6.87	-4.1%
Gene Steratore	13.39	+3.9%	7.13	6.26	+6.5%
Walt Anderson	15.04	+3.7%	7.75	7.29	+3.1%
Tony Corrente	14.96	+3.2%	7.69	7.27	+2.8%
Ron Blum*	15.03	+1.7%	7.73	7.30	+2.9%
Jeff Triplette	14.81	+1.6%	7.37	7.44	-0.5%
Tom White*	15.52	+0.3%	7.62	7.90	-1.8%
Mike Carey	14.30	-1.9%	7.06	7.24	-1.3%
Bernie Kukar*	15.12	-2.5%	7.53	7.58	-0.3%
William F. Carollo	14.29	-2.5%	7.04	7.24	-1.4%
Scott Green	13.60	-4.4%	6.98	6.62	+2.6%
Walt Coleman	13.83	-5.9%	7.08	6.76	+2.3%
Bill Leavy	13.55	-7.5%	6.97	6.58	+2.9%
Peter Morelli	13.49	-8.1%	6.87	6.63	+1.8%
Bill Vinovich*	13.59	-9.5%	6.46	7.13	-4.9%
Bob McElwee*	13.33	-9.7%	6.40	6.93	-4.0%
Gerry Austin**	13.03	-10.5%	6.18	6.85	-5.1%
Dick Hantak*	12.38	-16.2%	5.94	6.44	-4.0%
League Average	14.60	0.0%	7.31	7.28	+0.2%

* - retired before last season
** - retiring before 2008 season
*** - 2007 was first season as referee

Looking at this chart, you can see that an officiating crew can deviate by about 10% from the average number of penalties called. This means that in 2007 terms (12.69 average calls per game), you’d expect about 11 calls from lenient crews and about 14 calls from strict crews.That difference only amounts to about three calls per game per crew. Small, but significant, as about half of those calls come from the discretionary call base I described in the introduction and will discuss more in future entries.

I included the home/road splits just to give people a little confidence in the impartiality of NFL officials. There is almost no difference in the total number of penalties called against home and road teams.

Officials who call less overall penalties seem to call fewer penalties against the visiting team. There is a 21% correlation between those two figures. That can’t be explained simply by a higher tolerance for false starts with noisy crowds, as the referees topping that list called far fewer discretionary penalties against visiting defenses.

That’s a mystery that may be worth pursuing down the road.

While developing Front Office Football, which is my primary job, I try to stay atop recent trends in the NFL. I’m constantly creating charts and looking at play-by-play breakdowns of each game.

These statistical studies make my job enjoyable. So much of programming is hard work, requiring long hours. It’s not always a joy. But what makes my job different from what I did back in the days I was confined to a cubicle is that I can choose what’s next. And I can spend some time every now and then just learning about football.

The best part of programming is taking the game, with its gigantic simulation engine, and tweaking its framework to best simulate professional football.

Last summer, I began hearing from customers that the penalty numbers seemed far too high. Sure enough, when I looked at the 2006 penalty data, I saw a considerable gap between what was simulated and what the NFL produced in real life. An adjustment was made for the next patch.

The data was startling. In 2005, there was an average of 16.21 penalties called per game. In 2006, that number dropped all the way to 13.14 per game - a 19% decline. That trend continues, by the way. In 2007, officials called 12.69 penalties per game, another 3% drop.

The fact of the matter is that officiating has a huge effect on the NFL. It’s said that, following the rules to the letter, there’s a penalty someone could call on almost every play. So, each year, the league trains its officials on interpretations and fields of emphasis, and strives to strike a balance between anarchy and field hockey.

As an aside, if you’ve ever been forced to watch a field hockey match, let’s say by a college girlfriend who should remain forever nameless, you’d understand that this is perhaps the most frustrating spectator sport ever conceived, because there is literally a foul stopping play every five seconds. It is absolutely impossible for two young women to approach each other carrying curved sticks and not violate one of the many rules of the sport. Field hockey referees wear out about six whistles during the course of a match.

The NFL must maintain that balance in the face of coaches and players trying anything and everything to gain an edge. It’s remarkable that in the last 65 seasons, the average professional football team has scored between 17.3 and 22.9 points per game. Those annual meetings with officials play a large role.

Mostly, we hear when officials are told to more actively enforce a rule. For instance, the media trumpeted, going into the 2004 season, that illegal contact would be a point of emphasis. Too many defenders were knocking receivers around. And, sure enough, the number of illegal contact penalties rose from 0.29 per game in 2003 to 0.68 per game in 2004.

As defenders grew accustomed to the new emphasis, penalties declined, and, in 2007, that number was all the way down to 0.39 per game.

What we don’t hear is when the NFL decides to relax the rules a little. Apparently, the number of penalties called in 2004 and 2005 slowed games down too much. Scoring wasn’t in decline, but game time had increased to the point where the fans were getting frustrated. So the interpretations on holding were adjusted and simplified. In 2005, there were 3.22 offensive and defensive holding calls per game. Last season, that number dropped to 1.96 per game - a decrease of 39%.

The whole Front Office Football process always has me thinking about issues surrounding the game. And when I adjusted the penalty numbers within the engine, I couldn’t help but wonder how individual officials affect the game. What if one official interprets a hold differently from another official? That’s inevitable, isn’t it?

So I took all the play-by-play reports from the last six seasons, going back to the 32-team realignment, and I broke down every penalty call. I reviewed 22,418 non-offsetting calls, and looked at how each official worked.

I divided penalties into three major categories.

1) Obvious Procedural Rules. These are penalties like false starts, illegal motion, encroachment, 12 men on the field, illegal forward passes and fair catch interference, where there’s little room for interpretation. Rules are rules, and officials have almost no discretion. I include most of the special teams penalties in this category, because interpretations are strict, and officials do a good job getting into position to see almost everything. Over the last six years, an average of 8.34 of these penalties are called in each game, about 40% are false starts.

2) Major Fouls. These are the 15-yarders, including severe face masks, unnecessary roughness, personal fouls, unsportsmanlike conduct and taunting. While there’s room for interpretation here, officials are given very specific instructions on how to handle player behavior, and, I’ve found, most referees not named Jeff Triplette call a fairly consistent number of these penalties (Triplette calls 27% more than the average referee, which is a far greater difference than any other official). There are an average of 1.42 of these penalties in every game.

3) Discretionary Calls. Here is where the officials earn their money. These are the calls central to controlling the pace of the game. For a defense, they include pass interference, illegal contact, roughing the passer and defensive holding. For an offense, they include pass interference, holding, illegal use of the hands and intentional grounding. I would venture that 95% of the training officials receive is concentrated on these fouls. There are an average of 4.84 of these penalties called in every game and there is tremendous variation among officials.

I concentrated this study on the small set of discretionary calls. While there might be only five of these penalties called in the average game (less than four in 2007), coaches have to be constantly aware of interpretations of these rules. What is holding? What will each official allow? How do you define roughing the passer? We’re all aware that quarterbacks receive more protection than ever before, but the penalty was only called 0.23 times per game in 2007, as opposed to 0.46 times per game in 2004. Defenders have adjusted.

In order to fully understand the role of officiating, I had to study up on how the NFL aligns its seven officials. The referee, who leads the crew, lines up behind the quarterback, and is pretty much solely responsible for roughing the passer calls, among other responsibilities.

The umpire, who is the poor soul who lines up just behind the linebackers and is constantly one step from annihilation, is responsible for most of the calls involving linemen.

The other five officials, who form a semi-circle around the defense, are responsible for handling the various receiver/defender interactions.

Ideally, my study would parse each official separately. But the NFL doesn’t report who threw each flag. So most studies assign all responsibility to the referee. After all, he is the man in the white hat who wears the microphone and has final say on all calls.

There are 17 officiating crews, and each usually works 15 of the 17 weeks during the season. By and large, crews stay together, though there are occasional injuries, and since many officials have another job, there are occasional scheduling conflicts.

I tracked only the referees and the umpires. While I can’t assume the referee, for example, can control how the side judge determines pass interference, there’s just no way to isolate the side judge from play-by-play data. A good cornerback will certainly know a little about each individual official, but I can’t make that adjustment, so I assigned those calls to the referee.

Since the umpires are so heavily involved with line calls - and thus throw the flag on more than half of all discretionary penalties - I decided to track their involvement separately.

In the next day or so, I’ll present some of my findings.

We want to welcome everyone to submit entries for our Sixth Annual NFL Draft Contest, which takes place on Saturday, April 26.

To enter, just fill out the form and submit your guesses for the 31 picks made during the first round of this year’s amateur draft.

The winner gets bragging rights as a draft expert for the next year, as well as a mention on Solecismic Software web site after the draft. Last year’s winner was Jim Gindin of Solecismic Software.

Have you ever tried the card game “Up and Down the River?” It’s also known as “Oh, Hell” or “Oh, Heck.” It’s a challenging trick-taking game where you bid based on a known trump suit. You score points based on taking exactly the number of tricks you bid.

Today, Solecismic Software released Front Office Card Games: Up and Down the River. You can download the game here. You can play the game on a limited free trial before deciding to purchase through electronic license.

Solecismic Software isn’t out of the football simulation business by a long shot. This is just an opportunity to try something new and generate a small amount of revenue while we’re in the process of developing our football products.