Comparing completion percentages of quarterbacks Kirk Cousins and Case Keenum over three seasons (2015-17) on various routes:
Comeback
Cousins: 54.7. Keenum: 45.7.NFL average: 52.7. NFL best: 67.2.Cousins TD/INT: 0/1. Keenum TD/INT:3/1.
Corner
Cousins: 44.4. Keenum: 36.7.NFL average:39.7. NFL best:57.4.Cousins TD/INT: 11/1. Keenum TD/INT:7/1.
Cross
Cousins: 71.0. Keenum: 74.7.NFL average:67.0. NFL best:80.0.Cousins TD/INT: 5/5. Keenum TD/INT:3/0.
Curl
Cousins: 81.3. Keenum:66.4.NFL average:72.7. NFL best:81.3.Cousins TD/INT: 2/4. Keenum TD/INT:1/4.
Flat
Cousins: 83.6. Keenum:80.5.NFL average:79.4. NFL best:86.0.Cousins TD/INT: 9/1. Keenum TD/INT:3/1.
Go
Cousins: 34.6. Keenum:38.2.NFL average:35.2. NFL best:50.2.Cousins TD/INT: 20/5. Keenum TD/INT: 1/2.
In
Cousins: 57.3. Keenum:70.0.NFL average:64.2. NFL best:75.9.Cousins TD/INT: 1/7. Keenum TD/INT:0/1.
Out
Cousins: 68.2. Keenum:63.7.NFL average:64.3. NFL best:73.6.Cousins TD/INT: 8/3. Keenum TD/INT:2/2.
Post
Cousins: 57.7. Keenum:50.0.NFL average:53.7. NFL best:67.0.Cousins TD/INT: 9/5. Keenum TD/INT:7/3.
Slant
Cousins: 67.0. Keenum:75.0.NFL average:65.7. NFL best:77.9.Cousins TD/INT: 13/4. Keenum TD/INT:2/2.
Under screen
Cousins: 90.6. Keenum:75.6.NFL average:79.9. NFL best:94.1.Cousins TD/INT: 2/0. Keenum TD/INT: 1/0.
WR screen
Cousins: 86.8. Keenum:86.5.NFL average:88.9. NFL best:97.4.Cousins TD/INT: 1/0. Keenum TD/INT: 1/1.
Receiver routes
Sportradar breaks down every throw into 12 different routes, and here's a brief description of each:
Comeback: Receiver sprints downfield, then stops and comes back toward the quarterback or sideline.
Corner: After running down the field, receiver breaks off route at an angle toward the sideline. (Sportradar counts fade routes in the end zone as corner routes).
Crossing: Receiver starts his route at an angle toward the middle of the field and continues running across the field. Sometimes called a drag route when done close to the line of scrimmage.
Curl: Receiver sprints, stops, then turns back toward the quarterback. Usually shallower than a comeback route.
Flat: When a receiver (usually a running back) heads toward the sideline close to the line of scrimmage.
Go: Receiver sprints down the field, typically in a straight line.
Out: After running straight, the receiver breaks off the route at a 90 degree angle toward the sideline.
In: After running straight, the receiver breaks off the route at a 90 degree angle toward the middle of the field. Also called a dig route.
Post: When a receiver runs deep downfield and then angles the route toward the middle of the field.
Slant: When a receiver runs a few yards then angles the route toward the middle of the field.
Underneath screens and wide receiver screens: When a pass receiver catches the ball near the line of scrimmage with blocking set up in front of them. Underneath screens often go to a running back.
Source: Sportradar