My passing offense metric, updated with last week's results. See below an explanation of the statistical details:  It's the same text I've posted in previous weeks.  The only difference is the minimum cutoff for making the list is 150 pass attempts.

History finally caught up with the golden boys last week.  Tom Brady had been putting up number of historic proportions, until the game against the Eagles, and his value has steadily declined since.  With his game against the Jets last week, his value finally slipped below Peyton Manning's 2004 season, which to date stands as the greatest in my database.  Similarly, Romo had been able to outperform his score from last year, which stood in stark contrast to other historically similar quarterbacks in my database.  To summarize my research, which has been mentioned here a couple of times before, last year Romo was 26 years old and recorded an impressive value of 0.508.  I compared that value against other quarterbacks in my database, when they were 26 years old.  I was pleasantly surprised to find him in exclusive company:  Quarterbacks who were in the Hall of Fame, strong candidates for the Hall, or frequent visitors to the Pro Bowl.  That convinced me, with very few reservations, that Romo was the real deal.  That was the good news, that our long search for a franchise quarterback was almost certainly over.

There was some bad news, though.  Rather than showing progress after their seasons as 26-year olds, all these excellent quarterbacks declined the following year.  So far, Romo had been able to stay above his value from last year, until now.  His stinker against Philadelphia announced loudly that you can run from history, but you can't hide.  Romo is now at 0.497, and will need two good games to finish above his score last year.

While his recent performance is obviously not good news for us Cowboys fans, I'm feeling confident about how relevant my system is.  It's a simple system, accessible to anyone who cares to perform a few simple calculations on a spreadsheet, and at least based on my research into Romo, quite robust.  I challenge anyone else to present a system that has both these characteristics.

Here's the intro I've posted on previous weeks:

I've been using a passing offense metric for many years now to gauge how well a QB is doing.  Inspired by baseball SABRmetrician Bill James, I performed linear regressions of NFL statistics and concluded from a big picture point of view, only two statistics mattered:  Yards gained from scrimmage, and turnovers.  The best fit to matching points scored came when assuming the following coefficients:

Ten yards gained from scrimmage = +1.0 points; and
One turnover lost = -6.0 points.

Simply put, teams that score points rack up yardage and don't commit turnovers.  Note how powerful turnovers are:  A team can, for example, gain 55 yards of offense, but if they turn it over the next play, they actually ended up hurting their team.

With that in mind, I created the points per pass metric, which calculates the effectiveness of quarterbacks.  The above two coefficients are used to determine, on average, how many points a quarterback (and his offensive teammates, since everyone else contributes to his success or failure) creates with each passing attempt.  It takes the simple yards per attempt metric we're all familiar with, adjusts it for sacks, and further adjusts it for turnovers.  One interception equates to minus six points; one fumble equates to minus three points.  I treat fumbles as half a turnover, since there's essentially a 50/50 chance of recovering or losing a fumble.  The results will probably be unsurprising for the most part, but sometimes they can appear odd.  One of the things that may cause these oddities are fumbles.  Most people, when looking over a QB's stat line, don't think about fumbles; they just look at yardage, attempts, touchdowns, interceptions, and maybe sacks.  But fumbles are very important, since they are essentially half a turnover.

Brady, NE                                        0.70
Garrard, Jax                                     0.61
Garcia, TB                                        0.56
Favre, GB                                         0.55
Manning, Ind                                   0.51
Romo, Dal                                        0.50
Anderson, Cle                                 0.49
Hasselbeck, Sea                             0.48
Cutler, Den                                     0.48
Brees, NO                                       0.47
McNabb, Phi                                    0.45
Schaub, Hou                                   0.45
Palmer, Cin                                     0.45
Edwards, Buf                                  0.41
Harrington, Atl                                0.41
Roethlisberger, Pit                          0.39
Warner, Ari                                     0.36
Rosenfels, Hou                               0.36
Campbell, Was                               0.35
Kitna, Det                                       0.35
Pennington, NYJ                              0.34
Rivers, SD                                       0.34
Jackson, Min                                   0.33
Losman, Buf                                   0.31
Manning, NYG                                 0.31
Culpepper, Oak                               0.30
Lemon, Mia                                      0.30
Griese, Chi                                      0.28
Boller, Bal                                       0.28
Bulger, StL                                      0.27
Huard, KC                                       0.26
Croyle, KC                                       0.26
Young, Ten                                     0.25
McNair, Bal                                      0.25
Testaverde, Car                              0.25
Grossman, Chi                                0.25
Clements, NYJ                                0.23
Smith, SF                                        0.18
Frerotte, StL                                   0.10
McCown, Oak                                 0.03
Dilfer, SF                                         0.01