In addition to selecting your primary receiver, you can change around your patterns. Some patterns work better against Man or Zone coverage, other patterns increase your chances of getting out of bounds, and other patterns attack specific holes.
For example, throwing a medium Crossing Route to a tight end against a two-deep zone coverage has an excellent chance of splitting the safeties and landing a big gain.
The patterns available to you depend on the receiver (back, tight end, or wide receiver) and type of pass (Short, Medium, Long). Here are the various patterns available in PSF.
SHORT PATTERNS
CIRCLE: 4 yards, best vs inside blitzes
FLAT: 2 yard2, good vs outside blitzes
FLARE: short, great vs outside blitz & zones
DELAY: very good vs RUN, bad vs PASS, worse vs blitz
ZOOM: 2-3 yards, big gainer vs blitz
HITCH: high-completion 5-yard pass
QUICK OUT: high-completion pass for 5 yards
SLANT: 7-8 yards, QB needs a little longer
SLANT OUT: good pass to tight ends
SLANT IN: good vs inside blitz
MEDIUM PATTERNS
Medium passes actually include two sets of routes, a 10-12 yard group and a matching but deeper group. In general, the 10-12 yard group is easier to complete, but the deeper routes can be better against 2-deep zones.
SQUARE OUT: 10-12 yard out route, difficult vs 2-deep zones
SIDELINE: deeper out (15 yards)
SQUARE IN: 10-12 yard pattern to inside
CROSS: 15 yard pattern across middle, difficult vs 3-Deep
HOOK: 10 yard pass, good vs Man coverage
COME BACK: Same as Hook, but 5 yards deeper
FADE: Very good vs Man coverage, particularly near the goal
DEEP PATTERNS
FLY: Excellent deep route for fast guys against Man coverage
POST: Good vs 2-Deep zones, or when no Free Safety, otherwise much worse
CORNER: Safer pass to outside, little tougher to complete
OUT AND UP: Great vs Man coverage, not against 3-Deep
OTHER PASSES
SCREENS: very poor vs Man coverage, and can be destroyed by blitzes, but excellent way to attack Pass/Zone defenses.

One thing about screens (and draws): They should do well against blitzes, but you say they “can be destroyed” by them. Teams use screens and draws to counter blitzes.
You’re right, and they can do very well. It depends on the execution and the teams/players’ ratings. I’ll double check that part of the code, though, to remember my notes. Thanks!
Great, thanks, Kerry.