Like many other Charger fans, I've been thrilled with Telesco's moves this offseason. I saw all the improvements to the trenches; I saw the return of Whiz, all the other little signings, and visions of Super Bowls danced in my head.

Unfortunately, I was looking at some numbers recently, and I noticed a major defensive issue that our team has, one that hasn't been addressed by any of the offseason moves. Let me explain:

(Warning: Numbers ahead)

Run Defense

The accepted explanation for our awful run defense laid the blame mostly on our D-line for failing to stuff the run.

If we check the numbers though (courtesy of Football Outsiders), we see that our stuff rate (stopping the RB at or behind the LOS) was ranked 25th in the league. That's not great. But it's not as horrendous as our overall rush defense rankings.

The real problems are on the 2nd level and the open field, where we ranked 31st and 32nd, respectively. THAT'S horrendous.

What does this mean?

Up front, we were okay at stopping the run. The problem was, once the RB made it 5 yards past the LOS, he made it further against us than he would've vs. almost anyone else in the league. Our safeties and LBs couldn't tackle.

What about Perryman?

Perryman took over full-time after the bye week. Up to then, we allowed 1.33 2nd level yards and 1.23 open field yards. Those numbers were 1.38 and 1.21 at the end of the year - slightly worse, if anything.

Our stuff rate did improve considerably (15% to 18%), he might be part of that, but overall he didn't seem to make much of a statistical difference.

How could we be so bad, we had The Beard?!

In the previous three years, our open field ranking has been 7th, 11th, and 8th. Even when our overall run defense was awful, we'd be bad at everything except this one stat because we had Weddle saving the day.

2015 Weddle was just not that player. At all. Everyone knows he dropped off this year, but I didn't realize how much his play hurt us until seeing these numbers.

Will we be better next year?

If the improved DL can stop more runs up front, that should boost our numbers across the board. So yes, kind of.

The problem is that we'll still probably be bad at pursuit and tackling. Lowery should be an improvement over 2015 Weddle, but that's the only change we've made, which worries me. And the same issue shows up in

Pass Defense

This time, I'm looking at YAC+, which is a Football Outsiders stat that means "how much average Yards After the Catch did the defense allow, compared to what an average receiver would've gained given that field position, down, and distance." It's a way to see which defenses were the best at shutting down YAC.

The Chargers had 0.85 YAC+, ranked 30th. This means that for every catch against us, a receiver got almost a yard further than they would against an average defense (almost two yards more than they would against Seattle). That's huge! And again, it means our safeties and LBs couldn't tackle.

How much does it matter?

Nine of the last ten teams to lead the league in defensive YAC+ made it to the playoffs. Six of the last ten teams to lead the league in YAC+ made it to the Super Bowl. That's incredible if you think about it, since it's a purely defensive stat, and it doesn't directly measure points or turnovers or anything. Not many stats correlate that closely with winning.

What else can we learn?

The FO numbers also suggest that we're really good at scheming things so that opponents throw short passes (see SHORT% and EFC%). We also had one of the best "failed completion" rates, where the pass is complete but doesn't gain enough yards to help.

We also surrendered the 5th most passing plays of 25+ yards, and the 6th most rushing plays of 10+ yards, so putting all the above together, I conclude the following:

1) Our scheme is good at forcing runs and short passes

2) We frequently allow short gains to turn into long ones

Or, to put it another way: we play a bend-don't-break scheme, that consistently breaks.

Whose fault is it?

I'm not sure; I'd be interesting in hearing comments. I'm inclined to say it's more on bad execution than bad scheme, although "bad execution" is the fault of both the players and the coaches.

More specifically, FO notes that open field yards and YAC+ are strongly associated with safety play in particular. I don't know how we ranked in YAC+ in previous years, but last year both safeties were garbage, and we kept getting burned. It sucks that this is the one area of the roster where we didn't improve.

Conclusions

I've seen people blame our bad defense on a lot of things: lack of turnovers, bad DL, weak pass rush, poor LB coverage. But the numbers show that we were at worst slightly below average in turnovers, run stuffing, sacks, covering RBs, completion percentage allowed, etc.

The place where we were bottom-of-the-league was TACKLING to stop big plays. We don't get beat through the air, we get beat in yards after the catch, or runs around the edge. The other thing we were awful at was covering TE's, which often ends up on the safeties...see a pattern yet?

I'm happy our DL is better, and I think Hayward and an improved Flowers will help a lot. But the safety position is the only one that we were worst-in-the-league at.

(I know I'm not the first person to say "tackling" or "safety play" was awful last year, but I didn't think I'd find numbers suggesting those were our biggest issues)