No, the comparison is really stupid. That 2015 team quite obviously had a historically strong offense. By comparison, even "when healthy" this year's offense isn't even in the same ballpark. Yes, you can use the claim that pitching injuries have hurt our run differential this year, which they have, but you need to also then go back to 2015 and realize that in the same reference point (~first half of the season) we were actually a below-average pitching team in 2015. So in reality that +87 run differential was created almost entirely by the offense. Do you want to argue that a couple of injuries to Donaldson/Tulo/etc. is the ONLY difference between the first half offensive output in 2015 and 2017? That is silly, as even with Donaldson and Tulo back we are quite obviously an average-at-best offense this year. By comparison that 2015 team was first in Team wOBA and had scored nearly 80 more runs than the next highest scoring team (which is also almost the exact positive run differential they had...) in the 1st half of the season. We are 23rd and 26th by those metrics this season, and it ain't because Devon Travis is injured.