The strength issue peaked my interest so i looked at your last 4 games.
Here is the gross and net (less returns) for the last 4 games:
Gm......Punts...Gross....Net.....TBs
13...........14.........38.8....37.4.....1
14...........12.........41.0....39.3.....1
15...........14.........39.1....37.7.....1
16...........12.........41.4....36.3.....3
total........52.........40.1....37.7.....6
I also looked at the combined gross by quarter for the 4 games:
Qtr....Punts......Gross
1..........14...........40.4
2..........15...........34.0
3..........14...........42.6
4...........9............35.9
I think the stats by quarter are most telling. It looks like fatigue and/or morale are contributing factors. The gross for qtrs 1 & 3 is 41.4 and the gross for qtrs 2 & 4 is 6.5 yards per punt lower at 35.0.
You punted an average of 13 times a game. I know fatigue is replenished some at half time, which looks like a possible explanation (I'm not sure if morale gets the same bump). Your stamina is at 9. The difference between the 2nd & 4th qtr avgs is probably the number of punts.
Train stamina and see how it goes. It may get you a decent bump in average pretty quickly. IMO, you need more punting and vision. More points in Calm Nerves may help with being erratic (you have a lot of punts in the 45-50 yard range), but I would add to punting skill first. BTW, a piece of custom equipment will get you +6 punting and +1 to all SAs

Back to the strength question. He did have punts of 56, 56, 55, 51, 50, 50, 48, 48 in those 4 games. He is just really inconsistent. Soooo... punting > strength? OR a little more well rounded and he will be kicking for a 48 yard average? I'm still up in the air.
EDIT: arrrrrgh...stupid spaces disappearing when posting the table.