Possessions Recovered by Defensive Backs for his or her Team

Upon completing the last post, I began to wonder: What does INT% really tell us? Indeed, it serves as a statistical alternative to basic percentage of opponents’ passes a player intercepted. INT% attempts to account for the rate at which a player intercepts passes targeted for his assignment. But the actual data are increasingly available, if for a petty membership fee. So perhaps INT% would be useful for historical analyses. I am interested in statistically evaluating defensive backs in the present, however.

Once I completed the INT% analysis and write-up, I considered a statistic to rate defensive backs’ overall impact on opponents’ passing games, as a alluded to at the close of the last post. Ambitiously, I compiled official NCAA statistics for teams and players from 2004, the first year in which pass deflections were officially tracked, through 2014.¹ By the time I compiled all the necessary data and organized it, I had other ideas.

“What does an interception represent for a player and his team?”, I wondered to myself sitting in a theatre watching Pixels. Interceptions represent the gain of possessions for a player's team and the loss of possessions for opponents. That led me to this notion of a statistic to represent the proportion of possessions a DB recovered for his team via his impact on the passing game (i.e., via interception). Or, in other words, the volume of opponents’ possessions a DB ended.

Because team opponent possessions statistics were less than accessible for me, I simply tabulated estimates. To do so I summed each of all TDs scored, FGs, turnovers, punts attempted, and safeties for team offenses 2004 to ‘14, plus the quantity of games (to account for opening or halftime kickoffs). I would have included team attempted FGs but those were unavailable to me and also, blocked kicks but I got lazy. (Fortunately, for NFL stats, team opponent drive statistics appear readily accessible.)

Jayron Hosley defends a pass.

Now, I could have simply divided a DB’s interceptions by opponents’ possessions. But I sought a stat with greater nuance than a simple proportion. So first, in the denominator I divided opponent possessions by 11, the quantity of defensive players on the field. We’ll call that (Opp. Poss. / 11) possessions responsible for ending, or PRE. PRE operates on the premise that each defender is equally culpable for ending opponents’ possessions. However, r = 1 when Possessions Ended is correlated with the basic proportion, INT / Opp. Poss. 

At onset, I anticipated wanting to somehow weight the values in the numerator and denominator to reward the DB whose offensive teammates were counterproductive. For instance, in 2010 Jayron Hosley of Virginia Tech intercepted 9 passes. In 2006, John Talley of Duke intercepted 7 passes. For the seasons in reference, Hosley’s ended 5.4% of opponents’ possessions and Talley, 5%, proportionately. The Possessions Ended formula puts Hosley at .59 (8th highest) and Talley at .55 (tied for 12th highest).  

In 2010, VT finished 11-3 and 8-0 in ACC play whereas in 2006, Duke finished 3-9 and 1-7 in ACC play. Hosley’s 2010 offensive teammates relinquished only 13 turnovers and scored 80 times whereas Talley’s 2006 offensive teammates relinquished 31 turnovers and scored only 28 times. Thus, Hosley’s offensive teammates increased his PRE more so by scoring whereas Talley’s offensive teammates increased his PRE more so by fumbling and throwing interceptions.

So I settled on the Possessions Recovered formula above. I considered weighing Player Int’s by the sum of turnovers and punts but, although both are bound to occur, punting seems to me unproductive rather than counterproductive. With turnovers, Talley’s numerator is larger than Hosley’s because his offensive teammates generated more turnovers. In the denominator, I weighted PRE by scores. Therefore, Talley’s denominator is smaller than Hosley’s because his offensive teammates scored less often. Do note that Team Scores excludes safeties and includes TDs scored on defense and special teams.

Table 1 appears at the bottom of the page and includes the basic proportional possessions ended, the Possessions Ended, and Possessions Recovered, as well as the rankings for the latter two stats. I included in Table 1 players who were top 25 in Possessions Ended and Possessions Recovered to provide the reader some perspective on the nuance of Possessions Recovered. With Possessions Recovered we see that 2006 John Talley has risen to the number-one spot with 61.3% of PRE whereas 2010 Jayron Hosley has plummeted to 320th with 9.6% of PRE. We also find for instance, Chris Prosinski, presently three years into his pro-career, sitting at 14th with 30.3% Possessions Recovered. Prosinski picked off 3 passes in 2008 for a Wyoming team that turned the ball over 36 times and scored only 26 times. Possessions Recovered is also sensitive to interception totals as 2014 Gerod Holliman was at 8th with 34.1% for a Louisville team that committed 26 turnovers and scored 66 times.  

John Talley manufacturing yardage.

There are shortcomings to PE and PR, of course. PE essentially mirrors the proportion of interceptions to opponents possessions, as discussed above. PR is of course more sensitive to DBs who play for programs with counterproductive offenses. Surely other weaknesses could be identified. To improve either PE or PR, the quantity of passes deflected or broken up by a DB could be divided by three or four and that quotient summed with total interceptions in the numerators. Doing so is based on the premise that three or four downs ended by a deflected pass would equate to a possession. I would opt for four for parsimony. 

Let us return to the players discussed in my example above. Jayron Hosley was drafted in the third round of the 2012 draft by the New York football Giants. Some would describe his professional performance as "unsatisfactory." But what about John Talley? 

John Talley is one of 4 players for whom I had three years of data. His junior and seniors seasons rank in the top-10 of Possessions Recovered. But what became of Mr. Talley? Talley was rated 33 of 218 cornerbacks available in the 2007 NFL draft. Fellow 2007 DB prospects Leon Hall, Darrelle Revis, et al. are currently active on NFL rosters but like Al Worley before him, Talley passed undrafted (Worley: 172.3% of PRE for a 3-5-2 UW team with 38 TOs and 23 scores).

Talley’s pro-day weight of 171lbs is 20lbs under the average of the top-30 projected CBs in the 2007 NFL Draft. Perhaps a pro-day 40yd-dash of 4.61s resulted in Tally’s exclusion from the NFL Combine. None of first-30 CBs had 40yd-dash times slower than 4.56. The top-30 averaged about 15 reps on the 225lb-bench press; the lowest quantity, 10. Talley did 9. His 9’11” broad jump was slightly below average of 10’1” and a 32’6” vertical jump was below the average of 35’3”.

Talley’s 3-cone drill time of 6.77s was faster than the average of 6.96s and faster than 75% of the top-30. Considering 60 CBs drafted since 2005, Talley’s 6.77s on the 3-cone drill is in the 72nd percentile. Considering 170 WRs drafted since 2000, Talley’s 6.77 is in the 78th percentile, suggesting Talley may have possessed the agility necessary to compensate for the cutting and curling routes run by NFL receivers, many of whom would outsize, outleap, and outsprint him.

Talley deflects a pass targeted for Young Megatron.

In 2005 and 2006, John Talley was given the arduous task of guarding Georgia Tech phenomenon Calvin Johnson. Now better known as Megatron, the 6’5” Johnson and his 4.35s 40yd-dash were a mismatch for Talley. But Talley held his own in two Duke losses against GT. Johnson caught 4 passes in ’05 and 5 in ’06 for 73 and 78 yards, respectively. 

Talley held Johnson without a TD catch in ’05 while deflecting 1 pass and intercepting another. In ’06 however Johnson grabbed 2 TD catches only playing in the first half—due, at least partially, to a counterproductive offense that failed to keep Duke in the game. Of Talley’s 2 deflections of passes targeted for Johnson in ’06, one led to an interception.  

I briefly reviewed the box scores for the 2005 and '06 games, and by my estimation Johnson was targeted 8 and 7 times, respectively. If the box scores read accurately, then Talley actively defended (i.e., INT or deflection) 25% of passes targeted for Johnson in 2005 and 28.9% in '06.

Aside from Johnson’s TD production, his stat lines are nearly identical in the two games. Johnson suggested that he was triple-teamed in ’05; Talley contended otherwise but acknowledged that Johnson did demand “extra attention.” Likewise, Talley’s defensive production was similar in both games. Of Johnson’s 2 career tackles, 1 was of Talley in ’05. Summarily, in two showdowns with Talley, Johnson's production was tantamount to his collegiate averages. 

We know what Megatron became and what he continues to become. But as for Talley, his Twitter profile indicates that he is now a father. Since completing his BA in African American Studies at Duke in 2007, Talley earned his MBA back in 2012. From what I can gather, he currently teaches sixth grade mathematics.² In my opinion, following 18 years of education, Mr. Talley offers fair test-correction and tutoring policies to his students. Likewise, his expectations of classroom behavior are reasonable. Let us hope that as an educator, Mr. Talley’s pupils fare better with him than Calvin Johnson did—that is, let us hope Talley's pupils fare better than average.

Table 1. Top-25 NCAA DBs from 2004-2014 in Possessions Ended or Possessions Recovered³

Player	Year	Program	PE Rank	PR Rank	G	INT	Opp. Poss.	Team TOs	Team Scores	Basic %	PE	PR
John Talley	2006	Duke	12	1	12	7	139	31	28	0.05	0.55	0.61
Lionell Singleton	2006	Florida Int'l	109	2	10	5	142	26	20	0.04	0.39	0.50
Stanley Franks	2006	Idaho	3	3	12	9	145	26	36	0.06	0.68	0.49
Domonic Cook	2010	Buffalo	75	4	12	6	155	33	29	0.04	0.43	0.48
Anthony Smith	2005	Syracuse	68	5	11	6	152	27	27	0.04	0.43	0.43
David Amerson	2011	NC State	2	6	13	13	166	25	59	0.08	0.86	0.37
John Talley	2005	Duke	109	7	11	5	142	26	29	0.04	0.39	0.35
Brian Lainhart	2009	Kent St.	32	8	12	7	156	28	40	0.04	0.49	0.35
Gerod Holliman	2014	Louisville	1	9	13	14	178	26	66	0.08	0.87	0.34
Anthony Harris	2013	Virginia	18	10	12	8	167	26	42	0.05	0.53	0.33
Trae Williams	2006	South Fla.	22	11	13	7	149	29	47	0.05	0.52	0.32
Jack Williams	2005	Kent St.	248	12	11	4	146	31	30	0.03	0.30	0.31
Khayyam Burns	2006	Arkansas St.	181	13	12	4	129	30	33	0.03	0.34	0.31
Chris Prosinski	2008	Wyoming	430	14	12	3	151	36	26	0.02	0.22	0.30
Anwar Phillips	2004	Penn St.	191	15	11	4	132	27	31	0.03	0.33	0.29
Morgan Burnett	2008	GT	12	16	13	7	139	27	52	0.05	0.55	0.29
Senquez Golson	2014	Ole Miss	4	17	13	10	165	25	58	0.06	0.67	0.29
Sean Baker	2010	Ball St.	75	18	12	6	155	31	46	0.04	0.43	0.29
Rahim Moore	2009	UCLA	4	19	13	10	165	24	56	0.06	0.67	0.29
Eric Berry	2008	UT	10	20	12	7	135	18	36	0.05	0.57	0.29
Julius Stinson	2007	Wyoming	146	21	12	5	153	31	41	0.03	0.36	0.27
Dion Byrum	2005	Ohio	60	22	11	6	146	18	30	0.04	0.45	0.27
Reggie Corner	2007	Akron	37	23	12	7	158	25	45	0.04	0.49	0.27
Chaz Williams	2005	ULM	87	24	10	5	134	25	38	0.04	0.41	0.27
Charles Gordon	2004	Kansas	25	25	11	7	152	23	44	0.05	0.51	0.26
Dwight Lowery	2006	SJ St.	6	26	13	9	151	21	52	0.06	0.66	0.26
Kevin Sanders	2008	UAB	16	27	12	7	146	25	50	0.05	0.53	0.26
Quinten Rollins	2014	Miami (OH)	14	35	12	7	142	20	44	0.05	0.54	0.25
Quintin Demps	2006	UTEP	19	43	12	7	147	25	57	0.05	0.52	0.23
Ryan Smith	2006	UF	11	54	14	8	157	24	63	0.05	0.56	0.21
Daymeion Hughes	2006	Cal	9	87	13	8	153	22	69	0.05	0.58	0.18
DeAngelo Smith	2007	Cinci'	24	93	13	8	173	26	74	0.05	0.51	0.18
Larry Parker	2011	SD St.	22	164	13	7	149	16	59	0.05	0.52	0.14
Manti Te'o	2012	Notre Dame	15	186	13	7	143	15	62	0.05	0.54	0.13
Darcel McBath	2008	Texas Tech	19	203	13	7	147	21	86	0.05	0.52	0.13
Joe Pawelek	2008	Baylor	19	270	12	6	126	11	52	0.05	0.52	0.11
Robert Lester	2010	'Bama	7	274	13	8	145	14	77	0.06	0.61	0.11
Jayron Hosley	2010	VT	8	328	13	9	168	13	80	0.05	0.59	0.10
Anthony Wright	2009	Air Force	16	336	13	7	146	12	68	0.05	0.53	0.09
Al Worley	1968	Washington			10	14	136	35	23	0.10	1.13	1.72

Notes:

¹ All data were obtained directly from the Division 1 Statistics listed on NCAA.org; spreadsheets available upon request.

² Although I do attempt to provide the reader novel content, I refuse to make this an expose on a man's private life. But with some digital digging I was able to find this indicating Mr. Talley's status of educator. I have made an attempt to conceal identifiers of Mr. Talley's whereabouts and contact information in respect to his rights to privacy.

³ Shown at bottom is PE and PR for Al Worley. Team data for Al Worley were obtained from UW media guide here.