Biomechanical Re-Reviews: 2019 Early FA

Before the 2021 offseason makes way for training camp and the preseason, it’s time to take a look back at the player reviews of the 2019 season– 2019 being the year that the analytical methodology underlying these reviews began to mature. This first part will focus on the free agent reviews– Kareem Jackson, Bryce Callahan, and Ju’Wuan James. Each review will be posted in full (with a link to the original article at the bottom), followed by commentary based on how each player fared over the past couple seasons.

“Kareem Jackson is an anterior dominant player, favoring his medial areas. He shows full development in all biomechanical areas, with no obvious red flags for injury. On tape, he shows excellent recognition skills, with good anticipation and quick mirror movements. His long-speed however, appears to have diminished substantially with age. Although Jackson is quick to maneuver and make adjustments, he looks likely to struggle staying pace to pace with speedier receivers down the field. As a CB, he will likely need safety help over the top when covering fast outside receivers (and he may be forced to transition to safety if his speed continues to diminish). However, as an instinctual quick-reading/ reacting player, Jackson appears to be an excellent fit in Vic Fangio’s style of defense (which requires CBs to keep the play in front of them and read the play/ backfield). A great system fit, and a smart/ physical defender who can hopefully stay ahead of his age/ speed curve over the length of his Denver contract.”

Although the language here is a bit sparse (and these reviews went up prior to either of the two 3-part guides to understanding efficiency and borrowing being posted), this review showed itself to be accurate over time. Jackson was announced as a CB at his signing (and he was analyzed as such here), but this review correctly predicted that he might be forced to transition to safety due to age-related speed declines. In addition, while the word ‘borrowing’ was never used (since that term had yet to be explained), Jackson’s full development was specifically noted (full development precluding borrowing), as was his lack of red flags for injury. Jackson was described as a physical, instinctual, quick-reacting defender– traits that became apparent in Denver over the past couple seasons. And Jackson’s above-described continually eroding speed was likely why Jackson was released this past offseason (before being re-signed at a discount rate)– even for a safety, his speed became something of a liability at times this past season. Jackson was reviewed as an instinctual, physical defender who would likely play well (and stay healthy) for as long as he could stay ahead of his speed/ age curve, and this is what Denver received from Jackson over the past two seasons at safety.

“Bryce Callahan is a posterior dominant player, favoring his lateral areas. From the waist up, he appears almost like a clone of Chris Harris Jr.- similarly high levels of posterior/ lateral thoracic efficiency translate to strong ability to track/ redirect shifty receivers using the upper-body/ arms. Also like CHJ, Callahan appears very quick to react to the play/ receiver in front of him and is therefore an excellent fit in Fangio’s style of defensive backfield (hardly a surprise with his coming from Chicago). However, Callahan’s lumbar areas appear distinctly under-developed, particularly in the medial areas. It is almost certainly no coincidence that all 3 of Callahan’s career injuries involved his lower body. Although Callahan is a quick, physical, and instinctive defender, it appears likely that Callahan’s injury woes will continue in Denver. However, for as long as he is healthy, he will likely be a playmaker for Fangio’s defense.”

Again, this evaluation showed itself to be accurate over time, despite the sparse language. Callahan played how he profiled– as an excellent corner in the Chris Harris mold (and a playmaker in Vic Fangio’s defense), but one who continued to struggle with lower body injuries in Denver.

“Ja’Wuan James is an anterior dominant player, favoring his lateral areas. He shows good levels of anterior efficiency (particularly laterally), and is a quick-moving player. His 2018 anterior lumbar efficiency appeared compromised; however a review of his 2017 tape suggest that this was due to injury in 2018 (disclosed as a patellar tendon injury). There are no obvious red flags for future injury. However, James may be susceptible to future repetitive stress-type injuries due to apparently-lacking posterior lumbar independence.

James’s posterior thoracic efficiency (upper body strength) is reasonably high for an anterior dominant player, but heavily balanced towards his lateral areas- his center-core strength is not terribly impressive. And his posterior lumbar efficiency is also lacking- he does not show strong leg-drive. In a gap-blocking/ man-blocking scheme, James would appear to be a potential liability, unable to drive his man backward or open holes with forward strength/ leg-drive. However, James’ mobility and lateral strength likely make him a much better fit in a wide-zone Shanahan/ Kubiak-style scheme. Teamed with a strong RG/ TE in a zone scheme, James may become a very effective player- this may be an instance where coaching plays a large role in a player’s success. However, from an individual biomechanical standpoint, James does not appear to be an elite system-agnostic tackle”

This review is hard to grade since James barely played in Denver. Although his under-developed posterior was noted indirectly (described as lacking independence between lumbar and thoracic areas, which only happens when areas are under-developed), current methodology would have focused more on this lack of posterior development, and how it predicted future repetitive stress injuries– this was noted but not properly highlighted. Obviously the scheme fit/ coaching effect described above never had a chance to appear. Overall, it is hard to give this review anything other than an incomplete grade, with the note that under-developed posterior areas would likely be given more attention using current methodology.

In retrospect, these FA reviews seem generally accurate, correctly predicting Jackson’s position shift and speed declines in an otherwise fully developed and impressive athletic profile, Callahan’s high level of play when healthy but likeliness to continue experiencing lower body injuries, and James’s tendency towards repetitive stress injuries (catastrophic ones including tendon/ ligament tears). Definite room for improvement in the writing/ descriptions (and in the focus given to development vs borrowing), but overall it’s clear that analytical methods were beginning to mature.

(link to the original post)

The upcoming part two of these look-backs will focus on the 2019 draft reviews