In 2021, a new method for analyzing QBs was established, wherein areas of full efficiency became the sole guiding factor (you can read the post introducing these methods here). Since then, this method has been successful in the negative– ruling out long term starting success for QBs who failed to show any areas of full thoracic efficiency. However it has also led to false positives, where QBs with one or more areas of full thoracic efficiency were thereby predicted to find long term starting success and failed to do so.
Since the negative end was found to be accurate but the positive end was not, additional gating criteria were added. In 2022, this post established additional criteria for posterior dominant QBs (introducing a baseline of anterior thoracic efficiency), which led to one modified prediction (Will Levis, despite showing one area of full thoracic efficiency (medial), did not clear the requisite baseline of anterior thoracic efficiency and was therefore predicted not to find long term starting success). Afterward, another counter example was found, this time with an anterior dominant QB.
Desmond Ridder shows one area of full thoracic efficiency (medial anterior). However, it became clear over time that despite excellent control on the horizontal plane, Ridder’s accuracy/ control along the vertical axis was lacking (likely due to posterior cervical stunting). Granted, Ridder landed in the worst possible scheme (a traditional vertically oriented Shanahan tree scheme), but it became clear nevertheless that additional gating criteria would need to be added to the predictive model. This time to include posterior efficiency (both cervical and thoracic) for anterior dominant QBs.
While in the sample used to develop the initial methodology in 2021 there were almost no examples of QBs who showed requisite thoracic efficiency on one side of the body but subpar efficiency on the other, as efficiency trends first discussed back in 2018 continue to accelerate, what was once a rare edge case is now becoming somewhat common. So all QBs will now be gauged not just by their strengths (areas of full thoracic efficiency) but also by the cervical/ thoracic areas on their weaker sides, to see if they meet newly established baselines.
CJ Stroud presents one of the most unique profiles studied in this space. In 2023 his profile was misidentified as lateral oriented anterior dominant and he appeared to fit a common type studied in this space– the QB who shows very even well rounded thoracic development/ efficiency but no areas of full thoracic efficiency (like Mac Jones, Jared Goff etc). However, not only was Stroud’s orientation misidentified (he is actually medial centric posterior dominant) but the nature of his power delivery was completely misconceptualized– because it is so unusual.
For almost every modern QB studied with recent methodology, there is a common pattern to QBs who show areas of full thoracic efficiency– the areas of greatest efficiency provide the bulk of the power (on the posterior) and the majority of steering force (along the anterior). Areas of greatest use drive/ direct the throw, while relatively inefficient areas generally contribute far less discrete force (generally being more tight/ borrowed against). The exceptions are generally the Mac Jones types who, lacking any areas of full thoracic efficiency, have instead developed a more well rounded/ evenly distributed throwing mechanism.
CJ Stroud is the first QB studied using modern methods who pairs what now appears to be one fully efficient thoracic area (medial posterior) with extremely even and balanced remaining thoracic areas. In fact these other areas are apparently so efficient that they often drive the throw with only minimal power delivery from that fully efficient medial posterior area. While elite QBs generally show multiple areas of full thoracic efficiency (Josh Allen and Patrick Mahomes each show 3 areas of full efficiency for example) those QBs (like other fully efficient throwers) drive their throws mostly from their dominant areas (based on orientation) with the other fully efficient areas slack unless needed (for an example of how this hierarchy functions, the beginning of this article explains it). However, CJ Stroud’s three non-fully-efficient thoracic areas are instead constantly involved in every throw– unable to fully release as per the definition of such areas, but also seemingly in full control. Offering constant power/ adjustments while the fully efficient medial posterior area almost imperceptibly (due to needing to provide so much less power overall) ‘drives the bus’.
If you study CJ Stroud’s throwing, there is surprisingly little variation of speed/ velocity/ trajectory for a posterior dominant QB (the types of QB who generally specialize in adjusting their fully efficient power delivery system, capable of endless nuance). Instead, there is almost a lazy quality, an ease which is deceptive. Generally the areas that ‘ease up’ on a throw are the least efficient. For Stroud, they are his most efficient. And this overall ease of throwing (look at his combine throwing drills for a perfect pad-less example) is due to a system that now appears to be perfectly balanced. Balanced in an inversion of every other modern elite QB.
Now is generally where there would be some takeaway listed. Such that perhaps with so many areas constantly involved in every throw that Stroud would potentially be more susceptible to injury disrupting his throwing mechanic. However, there is no evidence to suggest this as yet. The honest truth is that for genuinely unprecedented profiles (which Stroud’s appears to be) there are no real takeaways that aren’t pure speculation. The only takeaway is that there are no evidence based takeaways (for now), and instead this is a situation to wait and watch. The only evidence available so far (record setting rookie season), suggests that Stroud’s unique profile may end up being uniquely successful.
Similarly, Jayden Daniels (lateral oriented anterior dominant) presents a difficult profile for these methods to project. While he shows one area of full thoracic efficiency (lateral anterior), his power generating thoracic areas (posterior) appear somewhat overlapped. This can be seen in Daniels’s seeming inability to vary his throw velocity or trajectory beyond a fairly narrow range. Daniels shows very high levels of lumbar efficiency and runs very fast in a straight line, with excellent acceleration. However he appears to lack much lateral agility or run strength and does not easily evade tacklers (beyond simply outrunning them). The final piece of the puzzle– his cervical areas/ efficiency (field reading etc)– do not show any obvious problems (stunting/ underdevelopment). But neither do these cervical areas appear particularly efficient (at least in the limited ways that can be studied from football film).
While on the surface it would appear that a mobile QB who shows one area of full thoracic efficiency should be able to find long term starting success, neither Daniels’s throwing ability nor his rushing skills appear especially high level on their own. Which theoretically should leave Daniels’s cervical efficiency as the deciding factor– Daniels shows enough physical talent that with the right mental makeup he could easily find long-term starting success. And his final college season shows consistently good decision making and high level accuracy. But with physical talents alone that likely aren’t overwhelming enough to compensate for some amount of slowness reading the field or in play processing, more cervical info would be needed to reach a firm conclusion. Overall, there simply aren’t enough positive cervical markers as yet. A better way to assess Daniels’s cervical efficiency (or potential lack thereof) is still needed. One final note: Daniels’s slim build and tight posterior areas predict potential future injury issues (particularly with a straight ahead running style) unless he is able to mitigate his tendency to initiate contact as a runner
Spencer Rattler (medial centric posterior dominant) shows the requisite physical traits of a long term successful starting QB, but with one important caveat. Rattler’s fully efficient medial posterior thoracic areas appear to channel force through anterior areas that meets the baseline efficiency requirements for posterior QBs– Rattler shows excellent arm strength/ vertical control and very good touch (for a posterior dominant QB). Likewise, while Rattler doesn’t show tremendous speed/ mobility, his lumbar areas appear reasonably balanced and efficient, and he shows good pocket movement, with the ability to pick up an occasional first down as a rusher. The important caveat for Rattler’s profile is regarding his cervical areas (like with Daniels). Methods for analyzing cervical efficiency for lateral anterior/ medial posterior orientations are more primitive than for medial anterior/ lateral posterior players as yet. And Rattler does not show any obvious stunting/ underdevelopment. However, Rattler does show fairly poor cervical efficiency in ways that can be currently gauged. And on the field, he appears to struggle reading/ diagnosing zones, which would seem to fit with these biomechanical observations. So while Rattler otherwise appears to meet all the physical requirements of the position, it seems possible/ likely that Rattler’s field reading will be his Achilles heel.
Bo Nix (medial centric anterior dominant) on the other hand shows an interesting/ unique combination of very high cervical efficiency with well balanced and efficient– but critically not fully efficient– thoracic areas. In practice this means that Nix reads the field quickly and accurately (both along the vertical and horizontal axes), throws on time and often with good anticipation. But these methods suggest he will likely fall short of the level of arm talent generally required for long term starting success. Critically, anything less than one area of full thoracic efficiency inherently leads to an unstable system. Much like a submarine with a small leak will inexorably take in water, a QB whose muscles are unable to fully return to rest after each throwing motion will slowly accumulate fatigue and eventually overuse related damage. On a micro level (within one game), muscles become constantly contracted, building up lactic acid and losing power/ range of motion so that ends of games (especially with many attempts and hits taken) become more challenging. And as the hits and fatigue build up over the course of whole seasons (and especially after aging starts to take its toll) fatigue can become overuse and overuse can lead to a cascading set of increasingly serious ailments (usually starting with tendinitis/ osis and often ending in major tears/ chronic conditions). Given that Nix shows close to full efficiency, meaning it is relatively large muscles that appear to be chronically contracted (specifically his chest and traps), he seems likely to avoid the worst of these problems and play reasonably consistently for a while (he is also near the age apex for biomechanical efficiency which will likely help for now). But Nix also shows the effect of this lack of efficiency in his throws, which are generally not terribly forceful, and with accuracy that is often just a bit off (particularly deep). Nix’s high cervical efficiency appears likely to lead to quality field generalship and the ability to run a schemed offense to a high level (and by all accounts, Sean Payton’s scheme is a perfect fit for Nix). However, without truly high level lumbar efficiency (and Nix’s appears to be reasonably high, but not to the level of a true running QB), Nix’s throwing talent just doesn’t quite clear the bar established by almost every non-running QB studied by these methods. Close to full thoracic efficiency, in practice (and particularly over time) is a very long way from full thoracic efficiency. So while he may run the offense effectively in the short term, it seems unlikely that Bo Nix will become the long term starting answer at QB for Denver
JJ McCarthy (lateral oriented posterior dominant) shows some high level traits, but also appears to fall short of the required arm talent for long term starting success. McCarthy does not show any areas of full thoracic efficiency, with even his favored lateral posterior areas appearing to trigger some constant unintended contractions (most obviously seen when he is throwing across the field). Furthermore, McCarthy’s anterior cervical areas appear noticeably underdeveloped, strongly suggesting that McCarthy will struggle making quick reads across the horizontal plane of field (and studying Roman Wilson’s tape shows how often McCarthy failed to see him breaking open). McCarthy does show high levels of athleticism overall, with excellent mobility, arm strength and flexibility (to get throws off while being hit for example). And McCarthy is entering arguably the premiere situation for a rookie QB, landing on a loaded Minnesota offense, in an offensive system that plays to his strengths in the play action/ vertical passing game. So he may find some initial/ statistical success. But over time his lack of full thoracic efficiency (and anterior cervical inefficiencies) seem likely to preclude his finding consistent success as a starter.