After moving the chains again. The 49ers go spread offense. 1st down was
post#34 where Kap sends a throw over Boldin's head on a slant-flat. But this is the play that stands out the most to me when it comes to 'good playcall, bad execution' that I mentioned as a general theme in my first post.
All 5 routes are designed to get a horizontal stretch at the LB level, and in front of the deep defenders (black) to defeat Cover3's four underneath zone defenders. The formation spreads the field wide and creates a horizontal stretch. The side where Vance (89) lines up is important because it determines who the strongside hook defender is (blue) and where Kap should take his progression.
Like most horizontal stretches, this is an inside-out read. Kap's first read is Vance over the middle. From there, the strongside hook defender (blue) should tell Kap to look towards Kap's right (inside-out). Notice how the red routes are run at a greater depth. That's because they are both 2nd in the progression (so they curl later). Orange routes are set as bait for the curl/flat defenders to help the horizontal stretching.
The strongside hook defender (blue) sticks to Vance. That means the strongside curl/flat defender (red) is the only defender remaining on that side of the field, so red is in a 2v1 situation. Compared to the other side of the field that still has a hook defender + the curl/flat defender (two oranges).
If red moves to his right, he would defeat Boldin, but leave VD open. He will move to his left and cover VD.
This leaves Boldin open. Kap is seen pump faking to Vance. Kap should have red lighted Vance by now and moved to Boldin.
Kap scrambles around and throws it away. This is a rhythm throw (5 step concept). All routes are dead in the water after they curl. It was an easy read to see the strongside hook defender stick to Vance, so move outwards to Boldin. If Boldin is covered by the curl/flat defender, move outwards to VD.
Then a delay of game to make it 3rd & 15. Weak screen pass. Punt.