Got bored this morning and got a little inspiration from a RockyTopInsider article detailing some of the changes in offensive output from schools the year prior to Chaney's arrival and during his first year there. I took some of the data they compiled and extrapolated on it further.
2019 UT Season Projected Offensive Numbers based on Chaney's Average % Change
Calculated the percentage change in each school's Prior Year and 1st Year's: (1) Points Per Game; (2) Yards Per Game; and (3) Average Yards Per Play. You'll be able to see each stop's statistics below. I then calculated the average % change, and then used that mean to calculate a hypothetical "average" increase that could be expected to be seen this year for the Vols. This was a purely quantitative analysis.
2019 UT Season Projected Offensive Numbers based on Chaney's Purdue and UT % Changes
Their point at the end adds a good qualitative twist to it, which suggests that the Purdue and UT seasons are a greater indicator. This is due to those two seasons being ones in which Chaney took over with an incumbent QB, unlike others where he had to implement a new, unexperienced one. These numbers were a hybrid of quantitative and qualitative analysis.
The RockyTopInsider Article link is here:
How Big of an Impact Can Jim Chaney Have in 2019? | Rocky Top Insider
Conclusion
Both of these are good indicators of where UT's offense should be this year. Personally, I think it will be somewhere in between the two, with the YPG of the Purdue/UT chart more indicative (although still too high) for that statistic and the PPG and AYPP of the Overall Average chart being more indicative for that statistic.