Pro Football Reference Blog

I'm a closet JaMarcus Russell fan, if only because it seems like an overwhelming and disproportionate (even for being a Raider and the #1 pick) number of people seem to dislike the guy. He actually played very well at the end of last season, and posted similar numbers to Ben Roethlisberger and Joe Flacco. As a 23 year old QB who went through his first training camp in 2008, he was impressive.

But enough about Russell; what I'm curious about is Oakland's signing of Jeff Garcia. Specifically, can (or will?) Garcia help Russell reach his potential and become an elite quarterback? The broader question is this: does playing with a successful, veteran QB help a QB (after controlling for draft position) become a better QB? Is there anything to this mentor theory?

Anecdotally, we can think of lots of examples. Dan Fouts began his career on the same team as Johnny Unitas; Boomer Esiason joined the Bengals just as Ken Anderson was finishing up his career; Daunte Culpepper and Tommy Kramer started their Vikings careers behind Randall Cunningham and Fran Tarkenton; Chad Pennington learned under Vinny Testaverde; Tom Brady behind Drew Bledsoe; Ron Jaworski learned under John Hadl, Ken Stabler under Daryle Lamonica, John Brodie under Y.A. Tittle and Neil Lomax under Jim Hart. While the next two guys are outside the scope of my study, obviously Steve Young had Joe Montana and then Jeff Garcia had Steve Young. It's a little early to say, but the early returns on Aaron Rodgers are good, too. They're good for Matt Cassell, too, even if he becomes another Scott Mitchell, who himself learned under a HOF QB.

But there are just as many counter examples. J.P. Losman learned under Bledsoe, but he hasn't become Tom Brady; Todd Collins sat behind Jim Kelly; Rex Grossman was tutored by Chris Chandler. While the Bengals were lucky with Esiason and Anderson, they weren't so good with Jack Thompson (#3 pick in the '79 draft) teaming with Ken Anderson or David Klingler getting advice from Boomer Esiason. Tommy Maddox, Brian Griese and Jeff Lewis all went to John Elway University; Jerry Tagge (#11 pick in the '72 draft) teamed with John Hadl in Tagge's third -- and last -- year in the league. Dave Brown was the #1 pick in the 1992 supplemental draft, but even Phil Simms' tutelage couldn't save him. Joe Namath won a Super Bowl, but Richard Todd, the Crimson Tide and Jets QB who followed in his footsteps, underwhelmed. And before Young mentored Garcia, the 49ers drafted Jim Druckenmiller to be the QB of the future. What about the guy who mentored Young? Joe Montana also teamed with Matt Blundin, second round pick of the Chiefs in 1992.

Perhaps no one had it as good as Eli Manning. His father was an NFL QB, his older brother was an all time great QB, and he began his career learning under Kurt Warner. Ryan Leaf had Craig Whelihan, although Jim Harbaugh was in San Diego by year three. But let's move past the individual cases; there have been 333 quarterbacks drafted in the regular NFL draft between 1970 and 2004. QBs that did not play at all in their first three seasons were excluded from the study.

I ran a regression using draft value and quality of the mentor QB as my inputs and eventual quality of the drafted QB as my output. There quality of the mentor QB variable was insignificant. I also used the logs of the quality of the mentor and drafted QBs, and the mentor QB variable was insignificant. I also ran the study using only QBs drafted in the top 30 overall; same result.

In other words, this is one of those studies where the answer is zero. As in, there is no evidence I saw that suggests QBs become better because of the presence of a veteran, mentor QBs. That said, let me present the full results. A couple of words about the ratings.

The mentor ratings are based on the QB's NFL production (relative to replacement) up until the season in question. I picked the best mentor possible for each QB in his first three years, to mimic what Russell will have with Garcia. The "score" column at the end is the grade for each QB; the grades aren't perfect -- Vinny Testaverde's ahead of Tom Brady -- but the individual grades don't matter *that* much. The important thing as far as the regression goes is that Vinny Testaverde and Tom Brady are both well ahead of Rodney Peete and Pat Haden, who are both well ahead of Eric Zeier and Ty Detmer. Because of those things, I was hesitant to include the full list, but I thought you guys might want to run your own studies. So here goes.

player			dryr	pick	team	Mentor	              Mentor     SCORE
Tommy Kramer		1977	 27	min	Fran Tarkenton	       16744	 4697
Matt Blundin		1992	 40	kan	Joe Montana	       14687	    0
Dan Fouts		1973	 64	sdg	Johnny Unitas	       14193	13861
Mark Vlasic		1987	 88	sdg	Dan Fouts	       13938	    0
Scott Mitchell		1990	 93	mia	Dan Marino	       13589	 2428
Craig Nall		2002	164	gnb	Brett Favre	       12850	   27
Brian Griese		1998	 91	den	John Elway	       12664	 3167
Boomer Esiason		1984	 38	cin	Ken Anderson	       11858	 8926
Doug Gaynor		1986	 99	cin	Ken Anderson	       11858	    0
Jeff Lewis		1996	100	den	John Elway	       11341   	    0
Jim Druckenmiller	1997	 26	sfo	Steve Young	       11089	    0
Jay Walker		1994	198	nwe	Warren Moon	       11033	    0
Scott Secules		1988	151	dal	Dan Marino	       11006	    0
Jim Sorgi		2004	193	clt	Peyton Manning	       10660	  158
Tony Adams		1973	343	sdg	Len Dawson	       10376	- 232
David Jaynes		1974	 66	kan	Len Dawson	       10194	    0
Dean Carlson		1972	179	kan	Len Dawson	       10194	    0
Bruce Mathison		1983	272	sdg	Dan Fouts		9787	-  30
Glenn Foley		1994	208	nyj	Boomer Esiason		9448	  192
Stoney Case		1995	 80	crd	Boomer Esiason		9448	    0
Mike Boryla		1974	 87	phi	Roman Gabriel		9419	- 350
Turk Schonert		1980	242	chi	Ken Anderson		9417	  486
Todd Collins		1995	 45	buf	Jim Kelly		9135	  675
Elvis Grbac		1993	219	sfo	Steve Young		8977	 3808
Carlos Brown		1975	296	gnb	John Hadl		8961	- 230
Scott Hunter		1971	140	gnb	Bart Starr		8944	  489
Frank Patrick		1970	251	gnb	Bart Starr		8944	    0
John Reaves		1972	 14	phi	Roman Gabriel		8864	   84
Ron Jaworski		1973	 37	ram	John Hadl		8850	 5649
Brad Johnson		1992	227	min	Warren Moon		8817	 6317
Matt Hasselbeck		1998	187	gnb	Brett Favre		8809	 5865
Brooks Bollinger	2003	200	nyj	Vinny Testaverde	8803	   70
Kliff Kingsbury		2003	201	nwe	Vinny Testaverde	8803	    0
Neil Lomax		1981	 33	crd	Jim Hart		8698	 5431
Jay Schroeder		1984	 83	was	Jim Hart		8698	 3779
Jerry Tagge		1972	 11	gnb	John Hadl		8678	- 180
Craig Whelihan		1995	197	sdg	Jim Everett		8552	    0
Alex Van Pelt		1993	216	pit	Jim Kelly		8378	   98
Marques Tuiasosopo	2001	 59	rai	Rich Gannon		8322	    0
Dennis Morrison		1973	357	sfo	John Brodie		8293	    0
Joe Reed		1971	283	sfo	John Brodie		8293	- 190
Bucky Richardson	1992	220	oti	Warren Moon		8275	    0
Drew Henson		2003	192	htx	Vinny Testaverde	8260	    0
Doug Nussmeier		1994	116	nor	Jim Everett		8242	    0
Matt Mauck		2004	225	den	Steve McNair		8144	    0
Rusty Lisch		1980	 89	crd	Jim Hart		8044	    0    
Steve Pisarkiewicz	1977	 19	crd	Jim Hart		8044	    0
Ed Luther		1980	101	sdg	Dan Fouts		8043	    0
Chris Redman		2000	 75	rav	Randall Cunningham	7880	  152
Richard Todd		1976	  6	nyj	Joe Namath		7768	 2491
Pat Haden		1975	176	ram	Joe Namath		7768	 1709
Vince Ferragamo		1977	 91	ram	Joe Namath		7768	 1616
Browning Nagle		1991	 34	nyj	Boomer Esiason		7744	    0
David Klingler		1992	  6	cin	Boomer Esiason		7744	- 201
Donald Hollas		1991	 99	cin	Boomer Esiason		7744	- 233
Chad Pennington		2000	 18	nyj	Vinny Testaverde	7676	 3515
Patrick Ramsey		2002	 32	was	Mark Brunell		7608	  471
Wayne Clark		1970	198	sdg	John Hadl		7576	- 150
Jack Thompson		1979	  3	cin	Ken Anderson		7529	- 122
David Garrard		2002	108	jax	Mark Brunell		7480	 2065
Byron Leftwich		2003	  7	jax	Mark Brunell		7480	 1594
Steve McNair		1995	  3	oti	Dave Krieg		7477	 9659
Daunte Culpepper	1999	 11	min	Randall Cunningham	7381	 5491
Erik Wilhelm		1989	 83	cin	Boomer Esiason		7229	-  12
Craig Erickson		1991	131	phi	Steve DeBerg		7207	 1195
Casey Weldon		1992	102	phi	Steve DeBerg		7207	    0
Tony Graziani		1997	204	atl	Steve DeBerg		7207	    0
Steve Stenstrom		1995	134	kan	Dave Krieg		7103	- 105
J.P. Losman		2004	 22	buf	Drew Bledsoe		7090	  176
Mark Herrmann		1981	 98	den	Craig Morton		6876	   31
Tom Hodson		1990	 59	nwe	Steve Grogan		6641	    0
David Woodley		1980	214	mia	Bob Griese		6592	  607
Tommy Maddox		1992	 25	den	John Elway		6559	 1084
Rob Hertel		1978	131	cin	Ken Anderson		6548	    0
Kent Graham		1992	211	nyg	Phil Simms		6460	  761
Shawn Moore		1991	284	den	John Elway		6454	    0
Guy Benjamin		1978	 51	mia	Bob Griese		6297	   80
Doug Flutie		1985	285	ram	Steve Grogan		6287	 3981
Chris Simms		2003	 97	tam	Brad Johnson		6226	- 166
Don Strock		1973	111	mia	Earl Morrall		6170	  852
Rex Grossman		2003	 22	chi	Chris Chandler		6081	  614
T.J. Rubley		1992	228	ram	Jim Everett		6075	-  29
Luke McCown		2004	106	cle	Jeff Garcia		6036	    0
Jerry Golsteyn		1976	333	nyg	Norm Snead		5962	    0
John Navarre		2004	202	crd	Kurt Warner		5929	    0
Mike Elkins		1989	 32	kan	Ron Jaworski		5886	    0
Tom Brady		2000	199	nwe	Drew Bledsoe		5787 	 8263
Vinny Testaverde	1987	  1	tam	Joe Ferguson		5760	 8320
Jeff George		1990	  1	clt	Joe Ferguson		5760	 5576
Mark Malone		1980	 28	pit	Terry Bradshaw		5687	  427
Randall Cunningham	1985	 37	phi	Ron Jaworski		5676	 7011
Tom Owen		1974	322	sfo	Norm Snead		5624	    0
Carl Summerell		1974	 80	nyg	Norm Snead		5624	    0
Chuck Long		1986	 12	det	Joe Ferguson		5547	-  36
Gifford Nielsen		1978	 73	oti	Ken Stabler		5529	  258
Matt Kofler		1982	 48	buf	Joe Ferguson		5522	    0
Jeff Blake		1992	166	nyj	Ken O'Brien		5474	 4258
John Hufnagel		1973	348	den	Charley Johnson		5462	    0
Tony Banks		1996	 42	ram	Mark Rypien		5460	 1813
Todd Husak		2000	202	was	Jeff George		5455	    0
Eli Manning		2004	  1	nyg	Kurt Warner		5428	  732
Bobby Hoying		1996	 85	phi	Mark Rypien		5421	- 609
Marc Bulger		2000	168	nor	Kurt Warner		5394	 4033
Michael Vick		2001	  1	atl	Chris Chandler		5380	 3207
Ryan Leaf		1998	  2	sdg	Jim Harbaugh		5342	    0
Moses Moreno		1998	232	chi	Jim Harbaugh		5342	- 122
Michael Bishop		1999	227	nwe	Drew Bledsoe		5273	    0
Tony Eason		1983	 15	nwe	Steve Grogan		5193	 1325
Ken Dorsey		2003	241	sfo	Jeff Garcia		5169	    0
Dave Barr		1995	119	ram	Mark Rypien		5165	    0
Kevin Sweeney		1987	180	dal	Danny White		4993	- 257
Mike Buck		1990	156	nor	Tommy Kramer		4922	  143
Jim Everett		1986	  3	ram	Steve Bartkowski	4921	 8370
Hugh Millen		1986	 71	ram	Steve Bartkowski	4921	  505
Wally Richardson	1997	234	rav	Jim Harbaugh		4860	    0
Stan Humphries		1988	159	was	Doug Williams		4831	 2710
Dan McGwire		1991	 16	sea	Dave Krieg		4795	    0
Paul McDonald		1980	109	cle	Brian Sipe		4780	  285
Jesse Palmer		2001	125	nyg	Kerry Collins		4768	    0
Troy Taylor		1990	 84	nyj	Ken O'Brien		4732	    0
Josh McCown		2002	 81	crd	Jeff Blake		4679	  183
Rich Gannon		1987	 98	min	Tommy Kramer		4674	 8308
Craig Penrose		1976	107	den	Craig Morton		4653	- 211
David Humm		1975	128	rai	George Blanda		4604	- 201
Randy Wright		1984	153	gnb	Jim Zorn		4570	  257
Dean May		1984	138	phi	Ron Jaworski		4560	    0
Eric Zeier		1995	 84	cle	Vinny Testaverde	4538	  327
Mike Kirkland		1976	143	clt	Bert Jones		4533	    0
Tom Tupa		1988	 68	crd	Neil Lomax		4530	-  13
Perry Klein		1994	111	atl	Bobby Hebert		4472	    0
Jeff Francis		1989	140	rai	Bernie Kosar		4446	    0
Steve Pelluer		1984	113	dal	Danny White		4391	 1216
Jim McMahon		1982	  5	chi	Greg Landry		4382	 4196
Aaron Brooks		1999	131	gnb	Jeff Blake		4376	 3750
Danny White		1974	 53	dal	Roger Staubach		4354	 4799
Cary Conklin		1990	 86	was	Mark Rypien		4294	    0
Wade Wilson		1981	210	min	Archie Manning		4203	 3599
Oliver Luck		1982	 44	oti	Archie Manning		4203	-  40
Bradlee Van Pelt	2004	250	den	Jake Plummer		4187	    0
Kelly Stouffer		1987	  6	crd	Dave Krieg		4145	- 697
Tim Rattay		2000	212	sfo	Jeff Garcia		4092	  747
Mark Rypien		1986	146	was	Doug Williams		4058	 4867
Tom Flick		1981	 90	was	Steve Grogan		4004	    0
Brian Sipe		1972	330	cle	Bill Nelsen		3994	 4847
Mike Phipps		1970	  3	cle	Bill Nelsen		3994	- 585
Philip Rivers		2004	  4	sdg	Doug Flutie		3994	  678
Todd Marinovich		1991	 24	rai	Jay Schroeder		3886	-  37
Dan Manucci		1979	116	buf	Joe Ferguson		3849	    0
Dan Marino		1983	 27	mia	Dan Marino		3763	20856
Bob Holly		1982	291	was	Joe Theismann		3680	    0
Doug Hudson		1987	186	kan	Bill Kenney		3664	    0
Rusty Hilger		1985	143	rai	Jim Plunkett		3659	- 394
Shaun King		1999	 50	tam	Brad Johnson		3629	  410
Drew Brees		2001	 32	sdg	Doug Flutie		3591	 5998
Akili Smith		1999	  3	cin	Scott Mitchell		3568	    0
Charlie Batch		1998	 60	det	Scott Mitchell		3558	 1399
Sammy Garza		1987	216	crd	Neil Lomax		3530	    0
Jarious Jackson		2000	214	den	Gus Frerotte		3474	    0
Billy Joe Tolliver 	1989	 51	sdg	Jim McMahon		3402	  718
Steve Bono		1985	142	min	Tommy Kramer		3391	 2119
Lynn Dickey		1971	 56	oti	Charley Johnson		3383	 3756
Dan Pastorini		1971	  3	oti	Charley Johnson		3383	 1143
Steve Ramsey		1970	126	nor	Charley Johnson		3383	  570
Billy Joe Hobert 	1993	 58	rai	Jeff Hostetler		3383	  179
Matt Cavanaugh		1978	 50	nwe	Steve Grogan		3317	  406
Jonathan Quinn		1998	 86	jax	Mark Brunell		3282	- 243
Seneca Wallace		2003	110	sea	Matt Hasselbeck		3235	   59
Scott Covington		1999	245	cin	Jeff Blake		3224	    0
Jim Harbaugh		1987	 26	chi	Jim McMahon		3066	 5447
Cliff Olander		1977	128	sdg	Bill Munson		2967	    0
Steve Myer		1976	 93	sea	Bill Munson		2933	    0
Dave Walter		1987	307	cin	Boomer Esiason		2916	    0
Cody Carlson		1987	 64	oti	Warren Moon		2886	  478
Kordell Stewart		1995	 60	pit	Mike Tomczak		2854	 2417
Kyle Boller		2003	 19	rav	Kordell Stewart		2842	   87
Sage Rosenfels		2001	109	was	Brian Griese		2813	  397
Matt Schaub		2004	 90	atl	Michael Vick		2738	  645
Mike Kruczek		1976	 47	pit	Terry Bradshaw		2729	- 162
Carson Palmer		2003	  1	cin	Jon Kitna		2722	 4095
Ken O'Brien		1983	 24	nyj	Richard Todd		2701	 5218
David Norrie		1986	291	sea	Ken O'Brien		2654	    0
Todd Blackledge		1983	  7	kan	Bill Kenney		2580	-  98
Steve Bradley		1986	316	cin	Jim McMahon		2573	    0
Rohan Davey		2002	117	nwe	Tom Brady		2571	    0
Frank Reich		1985	 57	buf	Vince Ferragamo		2383	  440
Jim Miller		1994	178	pit	Mike Tomczak		2297	  808
Steve Beuerlein		1987	110	rai	Jay Schroeder		2294	 4868
Chris Weinke		2001	106	car	Rodney Peete		2263	    0
Randy Fasani		2002	137	car	Rodney Peete		2263	    0    
Koy Detmer		1997	207	phi	Rodney Peete		2259	- 134
Marc Wilson		1980	 15	rai	Jim Plunkett		2234	 1079
Jeff Rutledge		1979	246	ram	Pat Haden		2221	  104
Steve Fuller		1979	 23	kan	Mike Livingston		2218	  726
Brett Favre		1991	 33	atl	Don Majkowski		2089	15851
Ty Detmer		1992	230	gnb	Don Majkowski		2089	  338
Peyton Manning		1998	  1	clt	Peyton Manning		2077	15664
David Carr		2002	  1	htx	Tony Banks		2026	  772
Kerry Collins		1995	  5	car	Steve Beuerlein		1999	 6119
Brent Pease		1987	295	oti	Warren Moon		1924	- 218
Rob Johnson		1995	 99	jax	Mark Brunell		1908	 1079
Dave Ragone		2003	 88	htx	Tony Banks		1888	    0
Gary Hogeboom		1980	133	dal	Danny White		1874	 1311
Gary Keithley		1973	 45	crd	Jim Hart		1822	    0
Mike Moroski		1979	154	atl	Steve Bartkowski	1815	  229
Mark Miller		1978	 68	cle	Brian Sipe		1797	    0
Anthony Dilweg		1989	 74	gnb	Don Majkowski		1791	    0
Pat Sullivan		1972	 40	atl	Bob Berry		1775	- 283
Mark Brunell		1993	118	gnb	Steve Beuerlein		1770	 8349
John Witkowski		1984	160	det	Gary Danielson		1763	    0
Mike Machurek		1982	154	det	Gary Danielson		1763	    0
Ben Roethlisberger	2004	 11	pit	Ben Roethlisberger	1757	 2371
A.J. Feeley		2001	155	phi	Donovan McNabb		1756	   60
Spergon Wynn		2000	183	cle	Daunte Culpepper	1724	    0
Jesse Freitas		1974	133	sdg	Virgil Carter		1656	    0
Neal Jeffrey		1975	423	sdg	Virgil Carter		1656	    0
Bob Avellini		1975	135	chi	Virgil Carter		1656	- 262
Bill Musgrave		1991	106	sfo	Steve Young		1639	-  47
Scott Bull		1976	177	sfo	Jim Plunkett		1638	    0
Eric Hipple		1980	 85	det	Gary Danielson		1637	  548
Brian St. Pierre	2003	163	pit	Charlie Batch		1635	    0
Steve Grogan		1975	116	nwe	Jim Plunkett		1612	 6009
Will Furrer		1992	107	chi	Jim Harbaugh		1557	    0
Peter Tom Willis	1990	 63	chi	Jim Harbaugh		1557	- 220
Rodney Peete		1989	141	det	Eric Hipple		1527	 2303
Chuck Fusina		1979	133	tam	Doug Williams		1523	    0
Sam Adkins		1977	254	sea	Jim Zorn		1508	    0
Jeff Komlo		1979	231	det	Gary Danielson		1498	    0
Kurt Kittner		2002	158	atl	Michael Vick		1494	    0
Ken Anderson		1971	 67	cin	Virgil Carter		1478	11726
Neil O'Donnell		1990	 70	pit	Bubby Brister		1329	 4898
Joey Harrington		2002	  3	det	Ty Detmer		1307	  453
Mike McMahon		2001	149	det	Ty Detmer		1307	- 321
Gibran Hamdan		2003	232	was	Rob Johnson		1277	    0
Brock Huard		1999	 77	sea	Trent Dilfer		1220	   78
John Elway		1983	  1	den	Steve DeBerg		1207	13164
Gary Kubiak		1983	197	den	Steve DeBerg		1207	-  87
Steve Dils		1979	 97	min	Tommy Kramer		1173	  275
Andre Ware		1990	  7	det	Rodney Peete		1161	-  16
Tim Couch		1999	  1	cle	Ty Detmer		1154	  756
Gary Marangi		1974	 70	buf	Joe Ferguson		1150	- 467
Leo Hart		1971	 59	atl	Bob Berry		1135	    0
Scott Campbell		1984	191	pit	David Woodley		1110	   12
Chris Chandler		1988	 76	clt	Gary Hogeboom		1088	 5107
Jack Trudeau		1986	 47	clt	Gary Hogeboom		1088	  466
Kim McQuilken		1974	 69	atl	Bob Lee	                1038	    0
Drew Bledsoe		1993	  1	nwe	Drew Bledsoe		1031	 7953
Archie Manning		1971	  2	nor	Ed Hargett		1023	 2820
Bobby Scott		1971	340	nor	Ed Hargett		1023	- 257
Danny Wuerffel		1997	 99	nor	Kerry Collins		1021	    0
Parnell Dickinson	1976	183	tam	Steve Spurrier		1013	    0
Neil Graff		1972	414	min	Jim Plunkett		1012	    0
Brian McClure		1986	313	buf	Jim Kelly		 964	    0
Rick McIvor		1984	 80	crd	Neil Lomax		 936	    0
Joe Montana		1979	 82	sfo	Steve DeBerg		 888	15151
Bill Cappleman		1970	 51	min	Gary Cuozzo		 887	    0
David Whitehurst	1977	206	gnb	Bobby Douglass		 885	   89
Dennis Sproul		1978	200	gnb	Bobby Douglass		 885	    0
Bubby Brister		1986	 67	pit	Mark Malone		 877	 1330
Jake Plummer		1997	 42	crd	Dave M. Brown		 847	 4919
Chris Greisen		1999	239	crd	Dave M. Brown		 847	    0
Donovan McNabb		1999	  2	phi	Donovan McNabb		 835	 7443
Jeff Carlson		1989	102	ram	Vinny Testaverde	 782        0
Joe Hamilton		2000	234	tam	Eric Zeier		 755	    0
Matt Robinson		1977	227	nyj	Marty Domres		 733	- 320
Rick Mirer		1993	  2	sea	John Friesz		 730	- 107
Gary Huff		1973	 33	chi	Bobby Douglass		 730	    0
Joe Barnes		1974	316	chi	Bobby Douglass		 730	    0
Larry Cipa		1974	373	nor	Archie Manning		 720	-  70
Mike Cherry		1997	171	nyg	Dave M. Brown		 667	    0
Danny Kanell		1996	130	nyg	Dave M. Brown		 667	- 367
Chris Miller		1987	 13	atl	Steve Dils		 667	 3344
Rich Campbell		1981	  6	gnb	Lynn Dickey		 647	    0
Troy Aikman		1989	  1	dal	Steve Beuerlein		 625	 8072
Don Majkowski		1987	255	gnb	Don Majkowski		 612	 1785
Tony Sacca		1992	 46	crd	Timm Rosenbach		 599	    0
Joe Gilliam		1972	273	pit	Terry Bradshaw		 591	  229
Cody Pickett		2004	217	sfo	Tim Rattay		 582	    0
Bert Jones		1973	  2	clt	Marty Domres		 577	 5895
Joe Germaine		1999	101	ram	Paul Justin		 569	    0
Gus Frerotte		1994	197	was	Gus Frerotte		 539	 3423
Vince Evans		1977	140	chi	Mike Phipps		 537	  947
Mike Pagel		1982	 84	clt	Mike Pagel		 536	  900
Art Schlichter		1982	  4	clt	Mike Pagel		 536	    0
Heath Shuler		1994	  3	was	John Friesz		 515	- 404
Blair Kiel		1984	281	tam	Gary Hogeboom		 498	  128
Bob Gagliano		1981	319	kan	Steve Fuller		 487	  124
Doug Williams		1978	 17	tam	Doug Williams		 474	 4668
Scott Zolak		1991	 84	nwe	Hugh Millen		 473	-  33
Cade McNown		1999	 12	chi	Shane Matthews		 466	  188
Jim Plunkett		1971	  1	nwe	Jim Plunkett		 403	 3186
Pat Ryan		1978	281	nyj	Matt Robinson		 378	  325
Joe Ferguson		1973	 57	buf	Dennis Shaw		 378	 4912
Dennis Shaw		1970	 30	buf	Dennis Shaw		 378	- 683
John Friesz		1990	138	sdg	Bob Gagliano		 354	 1318
Steve Bartkowski	1975	  1	atl	Scott Hunter		 323	 3996
Trent Dilfer		1994	  6	tam	Craig Erickson		 298	 1644
Norris Weese		1974	 99	ram	Steve Ramsey		 293	  420
Craig Kupp		1990	135	nyg	Chris Chandler		 293	    0
Quincy Carter		2001	 53	dal	Quincy Carter		 218	  664
Jim Bob Taylor		1983	280	clt	Mike Pagel		 148	    0
Mark Reed		1981	207	nyg	Mike Pagel		 148	    0
Terry Bradshaw		1970	  1	pit	Terry Bradshaw		 122	 7170
Craig Krenzel		2004	148	chi	Rex Grossman		  96	    0
Phil Simms		1979	  7	nyg	Joe Pisarcik		  78	 7238
Randy Dean		1977	117	nyg	Joe Pisarcik		  78	    0
Scott Brunner		1980	145	nyg	Phil Simms		  18	- 211
Steve DeBerg		1977	275	dal	none			   0	 5948
Bill Kenney		1978	333	mia	none			   0	 3914
Randy Hedberg		1977	196	tam	Gary Huff		   0	    0
Jeb Blount		1976	 50	rai	none			   0	    0

Occasionally (Marino and Bledsoe are examples), a QB will be so good by his third year and his "mentor QBs" will be so bad that the QB himself will become the mentor QB. Generally, this means the mentor QBs were essentially nonexistent -- guys who weren't very good and didn't stick around very long.

I didn't do an exhaustive analysis of the data, so perhaps you guys can find something interesting in here. Let us know your thoughts in the comments.