This post is in response to community members Fractal and onlyroses, who made valid comments saying they weren't sold the Air Raid could be effective in the Pac-12. I couldn't explain why it works and address your points in a few convenient and altruistic sentences, so I went all out and expanded it to a post. I like the questions you raised and think the discussion is very much worth having.
I'll open with some general thoughts.
"Hard to see how having 4 or 5 receivers run around in short and intermediate routes against 8 or 9 defenders, or against zone coverage, will work well, especially in a Pac-12 with a bunch of teams running spread offenses and our competition therefore having recruited LBs who presumably can handle coverage duties."
While the Air Raid burst into Division 1 in the SEC, a traditionally pro style conference - especially at the time (late 90's) - it gained traction and saw its highest levels of success in the Big 12. The Big 12 was home to as many spread offenses as the PAC-12 throughout the 2000's when Mike Leach's Red Raiders started beating people with regularity. If Leach's success was at all reliant on only going against teams not equipped, either scheme- or personnel-wise, to defend a spread offense, he wouldn't have found much of it in the Big 12.
However, speaking to your point Fractal, if you change the direction of your argument just a little I think it gains a lot of merit. As popular as spread offenses now are in college, they caught on more quickly at the high school level. High school football is typically on the leading edge of schematic innovation.
What does that mean? Current college linebackers, corners, and safeties likely played against the Air Raid, or some variant of it, in high school. Maybe they saw a lot of it, and maybe their own offense ran it. This certainly wasn't the case when Leach and Mumme brought the Air Raid to Kentucky and probably still not likely throughout his initial years at Texas Tech either. Defenders his Tech offense faced probably learned how to defend the Air Raid in college, now they might have some familiarity from high school. Is this the end all be all of whether or not his offense can be successful? I don't think so, but I definitely think it matters to some degree.
The answer why I don't think it's the all deciding factor dives into some X's and O's, so this makes for a good transition that direction.
First let's just dispel the ‘drop 8 or 9 guys' myth. Do teams rush with only two or three down linemen? Yes. All the time? No. Majority of the time then? Nope, not usually. They occasionally do it, and not just against the Air Raid, most spread offenses see a 3-man rush in spots. It is not an every down defense the Cougs see, I wrote this following the Oregon game last year. It is certainly not what keeps this offense from being productive on a scale of a full game. I've actually been wanting to chart how Connor does against certain fronts and coverages, but the Stanford game was gross and ESPNU derails all possibility of analysis with their camera work (OSU game). For now you'll just have to take my word, if you can. Dropping 8 doesn't happen as often as you'd think it does, maybe around 30% of plays in a series. It was much more common last season (~40%).
But the central concern remains valid; Throwing to 4 or 5 receivers running around against 8 or 9 defenders on 65-70% of plays doesn't seem likely to be effective, especially when there's no deception or misdirection (no play action).
I'll just hypothesize about what it is about that strategy that makes you think it's unlikely to be effective, and argue against it. Here's to hoping my intentional straw men fairly represent your position.
1. More defenders cover more space, so an offense that relies on wide receivers creating space would be negatively impacted by a team adding defenders in the secondary.
Yes. No way around that, it does, and that's why teams do it. But that strategy is not without its own weaknesses, which is why teams don't do it all the time. Running the ball is one, and we'll just put a pin in that for a minute and continue to focus on the wide receivers.
Each Air Raid route concept will have someone available to go deep, and no matter how many coverage defenders you add to the field, one level is going to feature a 1 on 1. Not everyone is double covered, despite a defense having the coverage numbers capable to do so at times. Single coverage is single coverage -- find the open guy -- so in that sense little changes. If that 1 on 1 is left to the vertical route? Giving a QB time with a 3-man rush can lead to a lot of explosives (use last season to notice how important time is here). Defenses know this, so most often the extra coverage guy is working double coverage of a route you aren't all that interested in hitting all that often anyway, playing over the top of a vertical. Back to a standard situation with your intermediate and short routes, this is where having routes spaced sideline to sideline and at all three levels is invaluable.
Each concept has a short route that demands linebacker coverage. You can think of linebackers like pawns against the Air Raid. Every play forces them to cover someone, every play they have to make a choice. Following a RB on a swing to the flat means opening the middle.
Linebackers aren't allowed to sit against this offense, they have to be active, therefore they move, and if they move, they create space. Substituting coverage backs for linebackers does decrease the match-up advantage for the offense, but it doesn't change the fact they have to move.
In the Air Raid, the pass plays are concepts because each route works in conjunction with the others in an effort to maximize open space. The vertical opens the shallow cross, the swing opens the mesh to the inside, and even triangle concepts work with three or four receiver routes. It is a field read for the quarterback, not a half field read, or single defender read.
Everything eventually boils down to a choice: One defender somewhere is going to be forced to defend one route over another, no matter how many coverage defenders you have on the field. Teams have opted for man coverage to limit that very weakness, so now you have to exploit the defender in man coverage that has no business trying to defend that route, which is only slightly more difficult. That's where the receivers need to up their game.
2. Play action disguises a play, if an offense can confuse a defense it has a greater chance of success.
Yes, it sure does for some teams. Let's avoid talking about the running game for just a bit longer ... if you can continue to bear with me. I'll lead by saying Leach's Air Raid has never been about deception. Some offenses are; his isn't. His is more about execution. His offense will run its plays better than you can defend them -- it's all about technique and execution. That's why the thousands of reps Leach talks about are so important.
Think about what play action tries to accomplish. That is, what movement in defensive coverage is caused by play action? Two things, mainly.
The first - linebackers are kept from taking their zone coverage drop. The running back is used to hold the linebackers at the bottom of their zones with the fake run. (I should note that play action loses its affect against man coverage, as the DBs aren't even looking in the backfield). The Air Raid does the exact same thing without play action. Running backs go through the line and out to the flat, or sit in the middle, or swing to the flat. Whatever they do, they occupy the linebacker's attention and manipulate his coverage drop.
The second - safeties that are active in run stopping are kept flat-footed. Part of the reason WSU has been eaten alive with play action this season is due to how much the defense relies on safeties for run support. Not many, if any, teams in the PAC-12 have a safety as their leading tackler (which Deone Bucannon is for the third time in four years). How many defenses are telling their safeties they need to focus on run support against WSU? Opposing safeties probably don't even care if WSU hands it off, or they shouldn't at least.
That doesn't mean the Cougs don't try. Halliday went deep to Marks off a play fake a few times against Cal. And it worked, as Marks got wide open. Play action can be very effective, even in this offense, but is not crucial for success. The main benefit, linebacker manipulation, is inherent to most route concepts to begin with.
3. Seems that there needs to be more variety and a more legitimate running threat, as we've seen with some of the Air Raid variants that Leach's former assistants have come up with.
Held off talking about the running game long enough. The way you phrase this is excellent. Variable and legitimate, completely agree. I don't think this offense will be successful without a running game that is both those things, and the latter probably follows the former.
Some people think a solution is running more. The Cougs average 19 rush attempts per game, and Leach's Tech teams were low 20's in attempts. If a team averages 2 yards a rush, why in the world would they do that more often? For some ancillary benefit of the defense not getting depth or taking attention away from the passing game? If you rush 2 yards an attempt, how much do you think a defense will de-emphasize their pass coverage efforts to stop your run? Probably not a lot, right? They need to become more efficient at running, not run more. I think this can come from, or at least be helped along by, variability.
Right now, the limited number running plays are variable only by offensive formation. And that's not a terrible way to do things. Leach has been very successful using that in the past. The thing is, WSU offensive sets are pretty limited right now. The Pistol lasted a hot minute last season and vanished, and now WSU is predominantly in 3 formations; Ace (4 WR, 2 x 2), Early/Late (4 WR, 3 x 1) , and Blue (3 WR, 2 RB, 2 x 1). I think it's safe to assume coaches Mastro and Leach didn't feel they have the personnel to try things in Pistol, whether they are true Pistol run concepts or Air Raid concepts ran from the formation, and it's pretty important to remember this line is only one year removed from being an atrocity.
The run game will improve -- as the linemen get bigger, more skilled, and more technically trained in the offense; as the quarterbacks become increasingly familiar with identifying coverage and deploying the offense, something that has to be based in experience; and as more scheme-friendly running backs are recruited. Marcus Mason has the Most Improved mid-season award in my book. He's getting visibly better every single game, but like every offensive position except WR, we haven't seen what a Leach-recruited guy looks like in there, yet.
As the run game becomes legitimate -- maybe through some variability, but maybe not -- the offense will be more effective because the average yards per play will increase if yards per rush increases. Defenses won't be 100 percent confident at the scheme they throw at a 3rd-and-5, and maybe more linebackers are in the game, regaining that slight match-up advantage. A lot of pressure is taken off the quarterback's shoulders, he can open up on first down knowing the running game can make third down manageable. Right now, completions on first and second down are almost mandatory for a drive's success (way less so than last year), and that limits what acceptable risk a quarterback is willing to take.
So why isn't everything working like clockwork now?
That's a million dollar question, or rather whatever a bowl game is worth, a few grand at least. I don't know the answer, but I think our community has crowd sourced some good theories over the season. Last year it was pretty easy to see the stylistic change was overwhelming and the talent gap was still pretty big -- we got into what the differences were last November. This year is a bit mysterious. I think the wide receiver talent may have been a little exaggerated, or to put it differently, how well we thought they'd take to the offense in year two was exaggerated. But the timing is infinitely better than last year, and the routes look a lot more crisp too. Guys are open, they just need to flip from receiver to playmaker in space, and I'm not sure how you foster that.
What I am entirely sure of is that the lack of success isn't endemic to the offensive system. It can work, it just needs the players. Look at what Goff (Cal) and Mayfield (Texas Tech) are able to do in terms of yardage, as freshman. Getting someone at the helm that's entirely comfortable with the system makes a big difference, and both of those guys ran it in high school. Halliday took a huge jump forward this season but needs to continue improving week to week; he's at a pretty big disadvantage trying to master it in a year.
Hopefully that addressed your points in a more specific manner. I think you were entirely within your rights to question the viability of the Air Raid. And I get the feeling a lot more people are drifting toward that camp this year than last year. It's always good to understand how things should work, so that you can identify how they aren't.