Yesterday, I chronicled the Moss effect.
Numbers within a vacuum don't mean much, however. The question was rightly raised as to how unique the Moss Effect is? Did Jerry Rice, Terrell Owens or Marvin Harrison have a similar impact as quarterback makers? Do all the great wideouts boost the productivity of quarterbacks, or was there something special about Randy Moss. Owens, Harrison, Rice and Moss are the four best wideouts since 1995. Studying their effect of on the quarterbacks they played with is illuminating.
In his prime, Montana played 75 games with Rice for a rating of 94.2.
Rice Effect: +3.6
Steve Young played 19 games for a terrible Tampa team, and spend the rest of his career in San Francisco playing with the 49ers. Obviously, it's not fair to make that comparison. However, we do have the 1997 season in which Rice played 2 games and caught 7 passes. That year, Young made the Pro Bowl with a rating of 104.7.
His rating without Rice was 86.8
Rice Effect: -0.6
Without Rice his rating was 80.5
Rice Effect: +12
However, Gannon had two Pro Bowl seasons in Oakland before Rice arrived. His Rice Effect in Oakland took his rating from 89.3 to 92.5 for a gain of just 3.2. Most of the 'Rice Effect' is mitigated by the system he played in in Oakland.
Hasselbeck without Rice had a rating of 89.0
Rice Effect: -5.9
Jim Harbaugh's passer rating with Harrison: 80.6
Harbaugh without Harrison 76.7
Harrison Effect: 3.9
Harbaugh's best year came in 1995 the year before Harrison arrived when he posted a rating of 100.7 to lead the NFL.
Paul Justin played briefly with Harrison, posting a rating of 81.4
Without Harrison, his rating was 59.9
Harrison Effect: 21.5
Note that Justin threw 113 passes in games without Harrison and 267 in games with Harrison. The samples are very small.
Peyton Manning's passer rating with Harrison: 95.0
Peyton Manning's passer rating without Harrison: 94.6
Harrison Effect: +0.4
Note: These numbers include the games Harrison missed with injury in 1998 and 2007 as games played without Harrison.
NOTE: I forgot Steve Young initially.
Steve Young with Owens: 98.5
Steve Young without Owens 96.1
TO Effect: +2.4
Jeff Garcia with Owens: 88.3
Jeff Garcia without Owens: 86.2
TO Effect: +2.1
Donovan McNabb with Owens: 99.5
McNabb without Owens: 83.5
TO Effect: +16.0
Tony Romo with TO: 94.7
Romo without TO: 96.8
TO Effect: -2.1
Ryan Fitzpatrick with TO: 69.7
Fitzpatrick without TO: 73.8
TO Effect: -4.1
Carson Palmer with TO: 82.4
Palmer without TO: 87.9
TO Effect: -5.5
Conclusion: the Randy Moss Effect is unique among the four elite receivers of the last 20 years. His boost to quarterbacks goes far beyond Rice, Harrison and TO. Owens actually had a negative effect on many of his quarterbacks. There is almost no difference between Manning's numbers with Harrison and without him.
For more amazing data on how effective quarterbacks were when targeting Moss, check out this amazing spreadsheet from Scott Kacsmar. Note especially Culpepper to Moss in 2004.