This article is a work in process. It's based on the best knowledge we have of how the stats actually work in the game at the current time. If you have more to add, sling it in a comment and I'll update accordingly. "I think it might..." is probably better left off unless you have some evidence to support it.

[DECREASES AT MATURITY] [CHANGES BASED ON WEIGHT] Max Speed - The speed your player runs at full speed. This is affected by the player's weight (in addition to weight gain or loss changing this stat). An 80 speed WR will be faster on screen than an 80 speed DT.

[DECREASES AT MATURITY] [CHANGES BASED ON WEIGHT] Acceleration - The rate at which the player achieves their top speed.

[STAT NEVER CHANGES] Strength - Ability to "push" other players. Also affects ability to break tackles. Maybe has an effect on forcing fumbles.

[STAT NEVER CHANGES] Intelligence - The only thing known for certain is that it affects ball carrier's attempts to cross the first down marker: rather than head in one direction for maybe more gain, they'll choose another if it makes the first down likely. Possibly affects QB decision making.

[STAT NEVER CHANGES] Discipline - Impacts the number of penalties a player causes. 100 discipline will not mean they never cause a penalty, but the number will be reduced.

Pass accuracy - Likelihood that the ball goes where the QB intends on a pass. Due to the nature of how this is calculated the improvements increase at very high levels. For example, 92 vs 95 accuracy has a similar impact to 60 vs 75. There's no such thing as guaranteed accuracy as other factors impact the calculation.

Hard count - Ability for the QB to draw an offsides penalty against the defense. If it does anything at all it's marginal.

Arm strength - Not just the QB's passing range, also the speed at which the ball is thrown.

Passing release - Avoids the "that pass wobbled on release" callout which makes passes harder to complete.

Look off def - Potential to convince opposing defenders of a fake passing target. Sells dummies better. Might impact play action and draw plays.

Scrambling - High scrambling reduces accuracy penalties for passing while on the move.

Field of vision - Ability of the QB to spot the open man. May impact the speed of checkdowns (ie Is target 1 open, no? Is target 2 open? etc.)

Pass catching - Improves ability to catch the ball. A player with 100 catching will still drop passes. A player with 10 catching will still make catches. The player with the higher ability will drop fewer.

B&R avoidance - Receiver (obvs including TE, RB, FB) ability to shrug off bump & run and remain on their route.

Route-running - Receiver ability to run exactly where the play dictates. Bad route-running will lead to more missed catches. Route can be disrupted by bump & run.

Pass rec courage - Mitigates receiver nervousness when catching while covered. Presumably, this means that penalties in the calculation for making a catch while closely covered are reduced.

Tackle ability - Reduces the ball carrier's ability to break or evade a tackle.

Strip ball - Increases the tackler's ability to force a fumble. Likely works in partnership with strength and tackling but this is unconfirmed.

Break tackle - Ability to break through tackles. Affected by strength and weight.

Ball carrying - Amount of time a player can maintain top speed while carrying the ball. May impact fumble likelihood but this is unconfirmed.

Avoid fumble - Reduces likelihood that a player fumbles. A player with 100 avoid fumble will still fumble.

Run blocking - Proficiency at making blocks while the ball is on the ground. Useful not only for offensive line, but also for downfield players. Improved by strength. Think of blocking as being like Sumo. The raw skill, run blocking in this case, is how good the player is at stopping the opponent getting past. Strength factors in by stopping the blocker being moved by a stronger opponent.

Pass blocking - Proficiency at protecting the QB while in the pocket.

Short snapping - Reduces the likelihood of a fumbled snap. May also impact the speed a QB starts looking for targets, or hands off to the RB but this is unconfirmed.

Long snapping - Reduces likelihood of slow or fumbled field goal snaps. Unknown if it affects plays run from shotgun.

Pass rush - Ability to beat a pass block.

Run defense - Ability to beat a run block.

Punt strength - Distance a punt can be kicked.

Punt accuracy - Ability to land a punt precisely (high levels here increase the number of punts landing inside the 20).

Punt timing - Speed a punt is made. Too slow and it risks being blocked.

Kick accuracy - Ability to kick in a straight line.

Kick strength - Distance the kick travels.

Kick holding - Ability of the player to receive the long snap and hold it laces out for the kicker. Impacts accuracy.

Kick catching - Ability of the player to catch a kick or punt return cleanly and not immediately fumble it.

Punish receiver - Assumed to impact pass drops and fumbles. May have an effect on receiver confidence (ie the antithesis to pass rec courage)

Zone coverage - Aptitude for playing a zone defense.

M2M coverage - Aptitude for playing a man defense.

B&R coverage - Bump and run ability whereby the defender attempts to knock the receiver off their route or slow them down without incurring a pass intereference penalty.