There's an assumption that being aggressive (i.e., taking extra bases) should also lead to more outs on the bases, and the Red Sox have just decided it's worth being more aggressive.
Looking at data for outs on the bases and extra bases taken since 2013 in the AL, this is actually not the case. There is no relationship between extra bases taken and outs on the bases. If you tell me how many extra bases a team took in a given year, that tells me basically nothing about how many outs on the bases they had (r-squared=0.01).
This is a poor model of outs on the bases (BOS in red):
On the other hand, the identity of the team across the past four seasons is quite a good predictor of how many outs on the bases a team will have. Tell me a team's outs on the bases in 2014, and I can give you a pretty good guess how many outs they made in 2013 and 2015 and 2016. The Red Sox have been the second-worst team in making outs on the bases in that time. The only team worse is the Angels. So I guess the hard-ass manager theory is out the window (although BAL has made by far the fewest outs on the bases during that time). Worth noting that the teams with greater variation tended to have more than one manager, the teams with little variation tended to have just one.
This is a good model of outs on the bases:
Looking at data for outs on the bases and extra bases taken since 2013 in the AL, this is actually not the case. There is no relationship between extra bases taken and outs on the bases. If you tell me how many extra bases a team took in a given year, that tells me basically nothing about how many outs on the bases they had (r-squared=0.01).
This is a poor model of outs on the bases (BOS in red):
On the other hand, the identity of the team across the past four seasons is quite a good predictor of how many outs on the bases a team will have. Tell me a team's outs on the bases in 2014, and I can give you a pretty good guess how many outs they made in 2013 and 2015 and 2016. The Red Sox have been the second-worst team in making outs on the bases in that time. The only team worse is the Angels. So I guess the hard-ass manager theory is out the window (although BAL has made by far the fewest outs on the bases during that time). Worth noting that the teams with greater variation tended to have more than one manager, the teams with little variation tended to have just one.
This is a good model of outs on the bases: