Saturday, November 25, 2006

NFL Refs Affect Total Points Scored? (Peter Morelli and High-Scoring Games)

Do you think the total points scored in a game is affected by which referee crew is calling the game? In theory, this might make sense -- not every referee crew calls penalties exactly the same way so if one crew rarely calls offensive holding and teams are aware of it, the offensive lines can get away with what another crew would consider holding. As a result, in theory, both offenses would score more than expected and the total points scored will be higher than expected.

The idea that a referee's tendency would give a hidden advantage to both offenses is not new. For example, in Michael Lewis's book The Blind Side, he described on page 215 how offensive lineman Steve Wallace was happy to see his favorite ref Jerry Markbreit in a key game because Markbreit lets left tackles get away with a lot, including being a bit farther back from the line of scrimmage than they are technically supposed to be. The assumption is that Markbreit would give the hidden advantage to both offensive lines and therefore his games might tend to have more total points scored than expected.

But I am not sure you would see a direct correlation between penalties called and total points scored. For example, if a referee crew calls offensive holding tightly but is well-known for rarely calling defensive pass interference, then you'd expect the total points scored to be lower than usual, even though the referee crew calls less penalties than usual.

Post your guesses and how you think we can study this.

As an enterprising attempt at tackling this, we took an unrepresentative sampling of the NFL referee statistics just as a test -- the two refs that have the highest penalties accepted after 11 weeks and the two refs that hvae the least penalties accepted after 11 weeks (Gene Steratore, Ed Hochuli; Walt Coleman, Peter Morelli). We then compared the total points scored versus the average you'd expect from each team's offense. (To simplify our test, we ignored how strong the defenses were.)

The results?
Looking from week 1-11, there is a little variance in total points scored per game: Peter Morelli 24.3, Walt Coleman 21.4, Ed Hochuli 20.9, Gene Steratore 20.5. Hmmm, the two refs who call the least penalties have higher total points scored than the two who call the most penalties.

There is some variance between total points scored and what we would expect based on each team's offense: Peter Morelli +4.1, Gene Steratore +1.2, Walt Coleman +0.6, Ed Hochuli +0.4. Hmm, Peter Morelli who calls the least penalties stands out here.

How about a correlation between the net difference from weeks 1-5 and 6-11? There is a correlation of 0.11 for net difference (and a correlation of 0.36 for total points ignoring which teams were playing).

So far, I think there may be an effect for some, but not all, refs on the total points scored in the game. The biggest trend I see so far is that if you Peter Morelli is the referee, expect more points scored than usual!

Data for Peter Morelli with actual total points scored versus expected points scored (average of offenses after 11 weeks) week-by-week: 34, 41; 61, 37; 35, 47; no game wk 4; 54, 40; 44, 40; 58, 50; 63, 41; 44, 45; 34, 41; 37, 31.

Or for Peter Morelli, actual compared with expected, week-by-week: -7, +24, -12, bye, +14, +4, +8, +21, -1, -7, +6. Six higher than expected and four less than expected (one of which was just -1).

Monday, November 13, 2006

Ref Watch Week 10: Tampa Bay Bucs and Carolina Panthers

Week 10 is coming to a close. Post comments on this game or the performance of the refs in any of this week's other games.

Tonight, Bill Vinovich is the referee for the Monday night game between the Tampa Bay Buccaneers and the Carolina Panthers.

Through week 9 (not including this past weekend's games), Bill Vinovich averaged 13.2 accepted penalties per game (6th most out of 17 refs). Only 44% of the penalties were called against the visiting team (least of all 17 refs). The penalty yards assessed against the visiting team averaged 13.8 yards less than against the home team (least net of all 17 refs). But no reason for Carolina to worry, home teams have won 83% of the games that Bill Vinovich has called this season from games 1-9 (2nd most out of the 17 refs). If that pattern holds up, Carolina would be in great shape to win.

But wait, the players decide the games, not the refs, right?

Saturday, November 04, 2006

Why Critique Referees...

One question is why fans would want to critique referees. In many sports, the people who could say the most about referees and their accuracy are banned from saying anything negative, so they are banned from expressing their views on this crucial topic. For example, the NBA fined team owner Mark Cuban $500,000 in 2002 for his disparaging remarks against the NBA director of officials. The NFL fined team coach Mike Shanahan $20,000 in 2005 for criticizing a ref's call. The NHL fined team owner Ed Snider and coach Roger Neilson a total of $75,000 for making public statements criticizing referees.

When players are banned from commenting on referees, it should be up to the sports journalists to analyze how well the refs did. But for some reason, most journalists do not criticize referees. One possibility is that they don't think referees make mistakes. Or maybe they don't think the mistakes are worth talking about. Or maybe they don't want to upset the sports leagues that give them the power to attend press conferences.

Analyzing the performance of referees is something that can be done with respect for how difficult it is to perform a referee's job. Let's call things as we see them -- if a referee makes a mistake, let's study it. Even the most honest and fair-minded ref will make a mistake once in a while. Making a mistake does not mean a ref is trying to help one team over the other. Remember that when an honest ref makes two mistakes in a game, there's a 50% chance that both mistakes will go against the same team.

But let's also criticize the sports where there are too many mistakes. Some sports have realized that there are too many mistakes and tried to fix their sport. In some sports, the NHL in 2000 adopted two referees (not just one) in each game. After the January 2003 playoff game between the Giants and the 49ers, the NFL revised how referees position themselves on field goal attempts. So criticism can be a good thing, a very good thing.

Justin Bloom, a columnist at, also wonders why criticism of referees is punished by professional leagues. He posted a column on October 31, 2006 titled "Invective directive: Why is criticizing officials so roundly criticized?"

Jeff Walker of the Avalanche-Journal is a Texas Tech supporter who believes coaches should be allowed to criticize referees. He wrote about it on November 4, 2006 in "Game Officials Should Be Called Into Account."

Criticism can get you suspended. Weber State football coach Ron McBride was suspended by the Big Sky Conference because he said "I think the guy just made a mistake" about a referee and that "I think it was an inadvertent whistle." Sounds like a small comment to get you suspended.

$12,500 fine against Titans coach Jeff Fisher for criticizing referee Jeff Triplette and umpire Jim Quirk for calling Mike Anderson of the Ravens down by contact and upon further review saying it was a fumble but no clear recovery. Fisher said it was a bad call by the umpire He also said that "we all saw it, everybody saw it" and "Now how you get down by contact I have no idea." Wow, $12,500 fine...

Wednesday, November 01, 2006

NFL Referee Report for the First Half of 2006

Today we analyze the first half of the 2006 season by NFL referee. Actually, the 2006 season has 17 weeks so we are analyzing slightly less than the first 50% of the season after 8 weeks. But let's call weeks 1-4 the first quarter of the season, weeks 5-8 the second quarter of the season, and weeks 1-8 as a whole as the first half of the season. How do the referees stack up?

We focus here on the following stats: total penalties, what proportion of the accepted penalties were called against the visiting team, and the win rate of the home team.

The following report is written based on three hypotheses: (1) some referees regularly call less penalties than others [we think this is true], (2) some referees call a greater proportion of penalties against the visiting team than others [not sure this is true], and (3) some referees call games where the home team wins more often [not sure this is true].

VP% = visitor penalty percentage -- if a ref calls all the penalties against the visitors, the VP% is 100%. So a higher VP% favors the home team.
HW% = home winning percentage -- if the home team wins every game a ref calls, the HW% is 100%. So a higher HW% favors the home team.

Post your comments on whether you think those three theories are true or not. Here we go, in alphabetical order, for all 17 head referees:

Walt Anderson: Visiting teams should be happy when Walt is the referee for their game. Home teams won only 29% of the games in the first half of the season (lowest or 17/17 for the refs). Walt has been pretty consistently bad for the chances that home teams will win -- in the first quarter, he was 16th out of 17 and for the entire first half he was worst for the home team, which is good news for the visiting team. Walt also calls a low number of penalties per game (1Q: 14th, 1st half: 15th). Week 1 controversial calls against home team New York Giants included offensive pass interference against Tim Carter and an illegal snap at the end of the game where the defense was not penalized for illegally calling a false snap count in a game that ended with the Indianapolis Colts winning 26-21. First half rankings: 15th in total penalties, 9th in VP%, 17th in HW%.

Gerry Austin: Gerry stands out for calling the highest proportion of penalties against the visiting team. For the first half, 64% of the penalties went against the visiting team. Otherwise, he is middle of the pack. First half rankings: 7th in total penalties, 1st in VP%, 7th in HW%.

Jerome Boger: Jerome stands out for tying for the worst winning percentage of the refs, with the home team, with the home team winning only 29% of the time. Jerome is climbing the ranks of total penalties per game, starting at 11th for the first quarter but at the halfway point has made his way up to 4th place. First half rankings: 4th in total penalties, 11th in VP%, tied for last in HW%.

Mike Carey: Mike is good news for home teams -- home teams win 86% of his games (best of the refs) and visitors are called for 60% of the penalties (3rd best). Mike also calls a large number of penalties, starting the first quarter with the most but cooling off to where he is now in third place at the halfway point. Week 6 controversial roughing-the-passer call helped home team Tampa Bay beat Cincinatti 14-13. Week 8 controversial call that Jets receiver Chris Baker was not forced out of the end zone while catching a potential tying TD pass in the last minute helped visiting team Cleveland beat the Jets 20-13. First half rankings: 3rd in total penalties, 3rd in VP%, first in HW%.

Bill Carollo: Bill has one of the lowest win-rates for home teams, ranked third-lowest of the refs. He is also trending upwards in VP% -- he started the first quarter with calling the lowest proportion of penalties against the visitors but has climbed to middle of the pack. First half rankings: 11th in total penalties, 8th in VP%, 15th in HW%.

Walt Coleman: Walt is great for the home team to win the game, even though he calls a large precentage of his penalties against the home teams. Go figure. He also calls some of the least number of penalties per game. Week 1 did not see Dolphins coach Nick Saban throw the challenge flag. First half: 16th in total penalties, 16th in VP%, tied-2nd in HW%.

Tony Corrente: Started off calling a large number of penalties (3rd in 1Q penalties) but cooled off and now is middle of the pack (9th). First half: 9th in total penalties, 15th in VP%, tied-13th in HW%.

Scott Green: Scott calls some of the highest proportion of penalties against the visiting team, yet the home team does not fare especially well in his games (winning only 43% of the time). First half: 8th in total penalties, 2nd in VP%, 12th in HW%.

Ed Hochuli: Ed is calling the most penalties per game thanks to a strong 2Q. After 1Q, he was only 9th but has rocketed to the top thanks to calling 17 penalties in week 5 and 16 penalties in week 6. But the inconsistency of his penalty numbers means he might fall out of the top spot in the second half. First half: 1st in total penalties, 14th in VP%, tied-8th in HW%.

Bill Leavy: Bill does not call many penalties per game, starting low at 16th in 1Q and rounding out the first half in 14th place. First half: 14th in total penalties, 7th in VP%, tied-4th in HW%.

Terry McAulay: First half: 12th in total penalties, 12th in VP%, tied-8th in HW%.

Peter Morelli: Peter is a shoe-in for calling the least number of penalties per game. He had 7.7 accepted penalties in the first half, well below the 8.7 accepted penalties per game for Walt Coleman who is his nearest competitor. Peter got the "lower hand" early on, with the lowest number of total accepted penalties in 1Q. Home teams do not fare well (43% win rate) in his games, could a hands-off attitude generally help visiting teams? First half: 17th in total penalties, 13th in VP%, tied-13th in HW%.

Larry Nemmers: Larry consistently has a large number of accepted penalties per game, 4th after 4 weeks and 2nd at the halfway point. Home teams win a good percentage of his games (71%). More fodder for the theory that a hands-on ref helps home teams and a hands-off ref is better for visiting teams? Week 8: ruled home team Vikings receiver Jerome Wiggins did not have possession before dropping the ball despite strong evidence suggesting otherwise and stuck to controversial call even after a replay challenge in a game where Patriots won 31-7. First half: 2nd in total penalties, 10th in VP%, tied-4th in HW%.

Gene Steratore: First half: 5th in total penalties, 6th in VP%, tied-8th in HW%.

Jeff Triplette: Jeff does not have many total penalties per game. Week 10: umpire Jim Quirk called Baltimore Ravens running back Mike Anderson down by contact and when Titans coach Jeff Fisher challenged, Triplette said there was a fumble, but no clear recovery, which Fisher criticized afterwards. First half: 13th in total penalties, 5th in VP%, tied-8th in HW%.

Bill Vinovich: started hot with the second most penalties per game after 1Q, but falling back where he is now in 6th. Home teams do well in his games (83% win rate), again supporting our growing theory that refs who call a large number of penalties are better for home teams (regardless of the fact that a large percentage of those penalties are called against the home team). First half: 6th in total penalties, 17th (last) in VP% (44%), tied-2nd HW%.

Ron Winter: Ron gets off without much commentary because he is last alphabetically. Anyone still reading this? Controversial call in Falcons 41-38 victory over the Steelers, with time running out in the fourth quarter, his crew called a false start penalty on Steelers Nate Washington with the 10-second runoff it ended regulation tied, which Steelers owner Dan Rooney criticized as "Those officials should be ashamed of themselves" (for which Rooney was fined $25,000) First half: 10th in total penalties, 4th in VP%, tied-4th in HW%.