Costello has the ability to deliver a ball with tremendous velocity. However, some of his balls tend to get lost in the air when he throws horizontally or diagonally.
Short Accuracy (1-10 yds)
The overwhelming majority of KJ Costello's throws are within 1-10 yards down the field. However, at this level of the field, he has often forced throws into tight/double coverage.
Imtermediate Accuracy (10-20 yds)
This is the area of the field where Costello struggles the most, especially in the red zone and in tight coverage. Part of this issue stems from miscommunication and bad chemistry with his wide receivers.
Long Accuracy (20+ yds)
In 2018, KJ Costello was delivering perfect passes deep down the field. Some of his biggest throws were deep down the field into tight coverage. However, he has been reluctant to target deep this year.
KJ Costello holds onto the ball way too long in the pocket. Especially with a worse OL compared to 2018, he needs to do a better job of getting rid of the ball within 4 seconds. He also needs to improve at holding onto the ball so that he doesn't lose snaps or get strip-sacked.
Costello can evade pressure and move around the pocket but rarely opts to pass once he starts scrambling.
This year, vision has been Costello's worst trait. He often fails to locate an open WR within 5 seconds, and forces throw into highly contested windows, even though he doesn't have the accuracy necessary to complete those passes.
Costello stands tall in the pocket and has proper leg mechanics, but has an awkward hitch in his throwing motion.
Since 2018, Costello has suffered a Concussion, along with thumb, ankle, and hand injuries. He is tough as nails but needs to slide earlier to mitigate the damage to his body.
Costello has no red flags when it comes to issues with his teammates or coaches and is known for being a great leader.
Costello isn't a decent game manager, but he needs to do a better job of speeding up the tempo of a game and moving the ball down the field.
Costello tends to force too many throws during a game and holds onto the ball way too long.
Costello has prototypical height and weight for a QB.
KJ runs a 4.94 40-yard dash time, which is average for QBs.
Costello doesn't have the accuracy necessary to be a big-time threat throwing the ball but can deliver a terrific throw on occasion.
KJ Costello was pretty efficient and productive last season but has seen his productivity deteriorate in 2019.
Costello has excellent poise, leadership, toughness, and coachability.
He's somewhat inconsistent from drive to drive, but not from game to game.
KJ Costello possesses decent arm strength and surprisingly good accuracy when throwing deep passes. While he isn't a dual-threat QB, Costello has enough mobility to evade pressure and gain some yardage on the ground. Although, some of his best attributes are his intangibles because he has excellent poise, leadership, toughness, and coachability.
In 2019, the biggest issue Costello needs to fix is his chemistry with his wide receivers. When Costello drops back to pass, he is often not on the same page with his wide receivers, and miscommunication leads to overthrows, underthrows, and questionable passes, especially along the sideline for some reason. The second biggest issue that Costello has pertains to his lack of vision. When Costello is going through his progressions, he struggles to locate open receivers quickly or forces the ball into contested areas. Furthermore, Costello's visual issues are one of the biggest reasons why he has problems in the pocket because he tends to hold the ball for 4+ seconds, which isn't ideal considering his OL isn't as good as it was last year.
While there are areas where KJ Costello needs to improve, he is far from the only problem at Stanford. Unfortunately for KJ, the WR and OL are highlighting his issues. For instance, he has to gain chemistry with an almost entirely new receiving corps from last year. Some of the new WRs are still struggling when it comes to route running and often break at the wrong time, or have miscommunication with Costello. This is partly what leads to his bad vision. Likewise, his OL is struggling to hold up against a 3 or 4 man blitz and let him get pressured too often. However, even when taking into account his team's shortcomings, Costello is still an underwhelming prospect. If he is unable to improve his play and draft stock, he will likely need to stay at Stanford for a 5th year, or risk being a low round pick.