Roster retention and success in the NFL

[KB_fan]

One of the earliest Huddle threads I posted after I joined last year was an attempt to analyze the Panthers' roster retention (from 2014 - 2015) and see if I could find any patterns in terms of retention & team success.

I was still a total newbie in terms of trying to think about and write about football statistics, and also I hadn't yet found many of the cool football stat geek sites I now know about...

One of the football stat geek sites I've found in recent months is Football Perspective.

Today they have a post on Roster talent retention from 2014 - 2015 and how it correlates with teams' winning % last season:

http://www.footballperspective.com/av-retention-rates-2014-2015/

First off, a quick note.  The analysis is based on "AV" - a metric developed by Pro Football Reference (PFR) to measure the contribution of each player on the roster to the team.  I've not dug too deeply into how they calculate it, but my understanding is that it's based both on snaps and performance.  I find it quite a useful tool to identify which players a team can least / most afford to lose. 

But don't get too distracted by that.  Here's Football Perspective's graph showing the relationship between roster retention from 2014 - 2015 (% of AV retained) and each team's win % in 2015.

 

Note that almost all of the playoff teams are towards the upper right of the graph.  High retention % and high wins.

So, of course, being the stat geek I am.... I couldn't look at this graph without immediately wondering what the Panthers outlook is for retention % in 2016.

It's looking EXCELLENT.  

Working from the 2015 Roster at PFR which includes the AV metric for each player, I did a quick and dirty calculation of our AV retention % from 2015 - 2016.

This assumes that all the players from last season's roster currently on the roster (46 of them) will make the 2016 roster.  Some probably won't of course, but most on the bubble have AV of 0 or 1 so even some change here won't affect the numbers too much.   It also assumes that a player's AV will be static from 2015 - 2016, but there's no way to know that now.  In fact, quite a few of our young returning players are likely to see AV increases (Funchess, Ealy, Boston, CAP, maybe even CJ will see a big jump in his AV if he stays healthy...), and some of the high AV vets could see declines if hit with injuries or their play time is cut to save wear on the tires...

I didn't include Kelvin Benjamin (who had a 2014 AV of 8) in the list below since he wasn't ever on the 2015 active roster.... but obviously getting him back is a big deal.

But for now, working with the figures we have, I calculate that Panthers are bringing back a pretty astonishing 83.6% of their team's approximate value from 2015.

Here's the breakdown:

(If the table isn't legible, try clicking on it, I think you will then be able to zoom in)

Exciting times to be a Panthers fan!

[KB_fan]

I had some time to kill while waiting for a meeting to start today and so I had a bit more fun with roster math and AV.

There is some very good evidence that DG has done a good job as GM.  (Most of us are already convinced of that, but if you want some hard numbers, I've got 'em.) 

The AV of players we added to the roster last year significantly exceeded the AV of the players we cut or let go:

• 53 points in AV added by draft picks and free agents in 2015
• 37 points in AV lost by players from 2014 who were not retained in 2015.  (This does not include players who were lost to injury:  KB, Chandler, Alexander)

Also, as for our coaching excellence and good player development, the AV of players who returned from 2014 dramatically improved in 2015.

• The 38 returning players in 2014 had 143 points in Approximate value in 2014.
• Those same 38 players had 203 points in AV for 2015 - a 42% improvement!

I'm going to try and go back to look at 2013 to 2014 as well.... and maybe do some comparison with other teams.  More later tonight.

[caatfan]

Of the ten players missing from last year's roster (so far), the average age is 31 (30.9), with only 3 guys under 30. That's a plus.

[KB_fan]

Football Perspectives also did this same roster value retention vs. wins analysis for the 2013 - 2014 season.

http://www.footballperspective.com/av-retention-rates-2013-2014/

Once again, high retention of roster value and wins show some correlation....

I'm almost done analyzing Panthers roster retention for 2011 - 2015 as well as the difference each year between total value (AV) cut vs. total value added, and also the improvement or decline of continuing players year to year....

Not sure if I'll post more tonight.  Maybe tomorrow...

[TheSpecialJuan]

impressive