Ok lets pick this up while I have a small window of opportunity. I may go back and flesh some of these ones out more since they are kind of short and to the point since I wrote these up while my computer was dying last Saturday and would have posted them then but you can only have 5 attachments per post so I lost what little time I had breaking the one long word document up into two separates meaning I only got one up.
Mesh is another take on how to use a shallow cross, it's main aim is to create a rub between the two crossing WRs thus making it extremely effective against man coverage. With that said depending on the routes around the main concept it can be used as a horizontal stretch (using wheel routes) or even using a high low read to allow you to take the top off the defense.
Y Cross is nothing more than a weakside flood using many of the same principles you'd get from Sail or Strong Flood. Its got all your basics covered for a vertical stretch flood play. There are 3 WRs running at one side of the field at 3 different depths (intermediate, short, and deep). What makes this different is that it brings its main target from across the field rather than loading up 3 WRs all on one side. This lets you run Y Cross out of a variety of formations from 3X1 with the flood happening on the 1 side or something as constricted as I Form Tight Doubles where you flood using the TE and the FB along with the lone WR. This along with Strong Flood (or Sail as the Air Raiders tend to call it) were the main calls against zone defenses in the early days of the Air Raid.
Shakes is a simple 3 vertical concept that uses deep corner routes with a deep seam. It aims to do exactly what 4 verticals does while giving you a more complete protection scheme since you can now block 7. It attacks the outside deep defenders on the sidelines while attacking the middle with the seam route. You can run this with a traditional 9 routes if you have too but its best to run it out of a corner strike play if you can. When running it with regular 9 routes is important to use the next concept to play off of it.
This will look like your standard 3 vertical concept (with 9 routes) except instead the two outside guys will stem their vetical routes off 15 yards downfield and cut back towards the sideline. Its a timing heavy concept that looks to attack loosing man coverage and loose zone coverage. Its best used in conjunction with Shakes since they are technically two sides of the same coin and in a real NFL book you'd see them drawn up as part of the same concept where the WR has the option to comeback if he sees the right coverage.
Simple way to attack the shallow sidelines. your flankers run 9 routes while your slots run shallow speed outs putting strain on the CB to pick between covering the 9 route or the speed out. Its a great way to beat zone blitzes as well as man coverage. It will have a small window to hit the out routes against cover 4 but cover 3 and cover 2 will cause it all sorts of problems so look to the check-down route if you get stuck against those coverages.