...like a golf swing.
If you have a "tired leg" you start to see the same problems as if you have a tired swing.
I am not privy to the warm ups of Folk or the practice sessions, but for those who are able to attend the games and see pre-game warm ups look for this:
1. Does the kicker look like he is overkicking, almost "pushing" his leg through the ball. It's an odd look and typically not very smooth from the contact point and after.
2. The ball will tend to go flatter. When a kicker has a tired leg they will overkick just to maintain distance, but you see more line drives which are counterproductive to coverage teams.
3. Contact with the ball sounds muffled due to pushing through the ball. Not the typical cannon shot of a solid kick. If anyone has ever held for a NFL calibre kicker or watch pregame warmups you know the sound a kicker's foot makes when he hits the ball square.
If he is trying to maintain height, then you will see the kickoffs get progressively shorter and it will be very obvious. Height is harder to achieve than distance.
3. A kickers warm ups will be sluggish. Things like high steps and such that you typically see kickers do in their warm ups will be slower and harder to repeat.
If there is a "tired leg syndrome"and I have seen it, the coaching staff will begin to reduce the amount of practice kicks in practice and pregame sessions.
Folk's a young guy and I would considering watching him carefully around the (12) game mark when they typically well beyond the collegiate limit of competitive kicks.
It is the NFL and there is definitely a ramp up in the level of performance needed to succeed.
There's no doubt we haven't seen the touch backs of the earlier part of the year, but without being on the field next to Folk I personally couldn't evaluate whether our rookie kicker has a tired leg or not.
Of the two kickers the one I feel who is not performing to his usual self is McBriar. It looks on TV like Mat is contacting the ball well, but we just haven't seen the distance on the ball we were treated to last year.