Over the past year, much biomechanical study has gone into quarterbacks, trying to determine the baseline physical requirements of the position. At the risk of stating the obvious, quarterbacks are both the most important players in football, and also the hardest to project in transition from college to the NFL. So a method of predicting NFL quarterback success by analyzing college level biomechanical efficiency– if reliable– would be highly useful.
Last offseason, a series of posts examined a new method for analyzing these players, wherein levels of full thoracic efficiency (explained in these posts) seemed to offer reasonably high predictive success (looking retroactively). Yet, this method predicted two things that have so far failed to materialize. One: that Zach Wilson would be a superstar quarterback (based on showing multiple areas of full thoracic efficiency). And two: that Drew Lock had franchise/ starter quarterback talent (based on showing one area of full thoracic efficiency).
So why has this otherwise seemingly reliable method– which accurately gauged so many quarterback futures when looking retroactively– failed in its evaluations of Zach Wilson and Drew Lock?
To answer this question, it helps to take an overview of recently studied players at the skill positions. Here is a chart of players studied over the past year, as well as their orientations.
| Medial Anterior | Lateral Anterior | Medial Posterior | Lateral Posterior | |
| QBs | Aaron Rodgers Josh Allen Desmond Ridder Matthew Stafford Joe Burrow Kyler Murray Carson Wentz | Justin Herbert Tom Brady Patrick Mahomes Jalen Hurts Mac Jones Teddy Bridgewater Deshaun Watson Trevor Lawrence Trey Lance Ryan Tannehill Matt Ryan | Dak Prescott Zach Wilson Sam Howell Kirk Cousins Baker Mayfield Jared Goff | Russell Wilson Drew Lock Davis Mills Justin Fields |
| RBs | Bryce Hall Zack Moss Jonathan Taylor Najee Harris Alvin Kamara Dalvin Cook Josh Jacobs Tony Pollard Ronald Jones Rhamondre Stevenson | James Robinson Saquan Barkley Derrick Henry Darrell Henderson Devonta Freeman | Antonio Gibson Damien Harris Aaron Jones Devin Singletary Javonte Williams D’Andre Swift Rashaad Penny Kareem Hunt Edwards-Helair Nick Chubb | Melvin Gordon Cam Akers Joe Mixon (?) Ezekiel Elliott Chris Carson Miles Sanders David Montgomery?Michael Carter Kenneth Gainwell |
| WRs | Drake London Tyler Lockett Hunter Renfrow DeAndre Hopkins Christian Kirk? Adam Thielen DeVonta Smith Jalen Reagor Tyler Johnson Jalen Waddle? | Jerry Jeudy Courtland Sutton Tim Patrick Denzel Mims DJ Moore Calvin Ridley Stefon Diggs | KJ Hamler Ja’Marr Chase DK Metcalf Cooper Kupp Davante Adams Tyreek Hill Mike Williams CeeDee Lamb AJ Brown Van Jefferson Brandon Aiyuk Marvin Jones? Chase Claypool | Kendall Hinton Tee Higgins Deebo Samuel Terry McLaurin Justin Jefferson Keenan Allen Diontae Johnson?Michael Pittman Chris Godwin Amari Cooper Rondell Moore Tyler Boyd? Jakobi Meyers Laviska Shenault Mike Evans?Garrett Wilson Brandin Cooks? |
| TEs | George Kittle Zach Ertz? Robert Tonyan | Greg Dulcich Kyle Pitts | Albert Okwuegbunam Travis Kelce | Rob Gronkowski? |
Ignoring the players with question marks for now (who need further/ more recent study to confirm orientation), there is a clear trend that emerges when taking this broad view. One that has shown itself to fall in line with historical trends as well. Which is that anterior dominant NFL quarterbacks outnumber posterior dominant ones by a fair margin. Given that the general population is split 50/50 between anterior and posterior dominance, this is noteworthy. And relevant to the discussion of Zach Wilson and Drew Lock.
Anterior muscle groups are, generally speaking, the control muscles. The muscles that are most responsible for accuracy and finesse. When throwing, posterior muscle groups supply the bulk of the force/ velocity, while anterior muscle groups channel/ direct that force. The back/ triceps push the ball forward, while the forearms, biceps and chest add directionality and small adjustments to the course of the ball. Which means that some baseline level of anterior efficiency is an absolute requirement for success at the NFL level. No matter how hard you can throw the ball, if you can’t direct it accurately towards its target, you will not succeed in winning games. And while posterior efficiency is linked with vertical accuracy (being able to subtly adjust the quantity of force being applied), in general, quarterback-related throwing accuracy is more commonly found in anterior dominant quarterback than posterior dominant ones.
So how does this apply to Drew Lock and Zach Wilson, both of whom show very high (and truly elite in Wilson’s case) levels of posterior thoracic efficiency? Despite their high levels of posterior thoracic efficiency, both these players show clear upper anterior thoracic tightness. Meaning that the upper thoracic areas (upper chest/ shoulders, connecting into the arms/ hands) on both players are somewhat stunted and unable to fire with subtlety and consistency. As a result, both players have generally needed ideal conditions to be able to throw accurately. If, at the last second, a defensive lineman lurches into their path, they are unable to step sideways and make quick anterior-related course corrections to their throw. Likewise, if something changes on a receiver’s route, or they spot a linebacker lurking at the last second, their anterior muscles–usually the quick-firing adjustment muscles- are unable to do their jobs quickly and consistently enough. No matter how subtle and accurate their throwing engine may be, if their course correction mechanisms are faulty, their accuracy will simply not be adequate.
This shows how, even in the case of Wilson with his truly elite posterior thoracic efficiency (an extremely rare two full areas of posterior thoracic efficiency translating to superlative depth-related subtlety and accuracy), the gating factor to his level of play is his anterior efficiency (or lack thereof). That no matter how efficient one’s posterior areas may be, in order to succeed as an NFL quarterback, there is a baseline level of anterior thoracic efficiency that must be reached.
Interestingly, Drew Lock actually shows greater anterior thoracic efficiency than Zach Wilson when he is throwing from a favorable stance (for a discussion of Drew Lock’s stances and fits in two recent schemes, please see this article). When Lock was playing in a Shanahan-tree system in 2019, the default Shanahan stance gave his anterior thoracic areas much more give to borrow from his anterior lumbar areas, so that even though his anterior areas were less favored by the stance, they were looser and less interferant with his fully efficient lateral posterior thoracic area. In other words, even though Shanahan stances favor posterior efficiency over anterior efficiency, Lock’s natural fit in this sort of stance may actually raise his available anterior thoracic efficiency above the required baseline level for an NFL quarterback. And if this is the case, then Lock’s fully efficient posterior thoracic areas will again be able to show their subtle use in a scheme predicated on vertical accuracy. It’s quite possible that with a return to playing in a Shanahan tree scheme in Seattle, Drew Lock may re-enter the starting quarterback spectrum of playing level and rejuvenate his career. That the apparent baseline level of anterior efficiency required to succeed in the NFL may finally be reached, and Lock’s potential realized.
However, taking again a more zoomed out perspective, adding a certain level of anterior thoracic efficiency as a pre-requisite for the position both explains the discrepancy in numbers between posterior dominant QBs and anterior dominant ones (since the anterior dominant quarterback will be much more likely to meet this threshold), and explains two of the NFL outliers who show areas of full thoracic efficiency but not necessarily this required baseline of anterior efficiency. Zach Wilson and Drew Lock (in recent seasons) simply haven’t met that bar.