In trying to explain why Farrell has played Young, I discovered two fascinating stats about this team in this so far very young season (which means things could change).
The first is that opposing managers appear to be terrified of sending lefties in against the Sox as starters or relievers. Betts, for example, has faced lefties in 6% (7 of 109) of his at bats, Pedroia about the same. Even Shaw, who has seen the highest percentage of lefties, still sees righties 80% of the time.
The second is that every single member of the regular lineup--Betts, Pedroia, Bogaerts, Ortiz, Ramirez, Shaw, Holt, both catchers, and Bradley--hits righties better than they hit lefties. Betts, granted, only hits righties slightly better--OPS 795 vs. 714. And Ortiz hits both sides well--over .800 against lefties and over 1.000 against righties. But almost everyone else hits righties three times as well as they hit lefties--like Pedroia, whose OPS against righties is .885 and against lefties .286.
Someone else might have the answer on why this is so, but I can only offer three possibilities: 1) season is young and the righty pitchers will eventually get good against our lineup; 2) lefty pitchers are a dying breed; 3) lefty pitchers are alive and well but by happenstance haven't faced us yet.
Let me add about our lineup is that we rarely have more than 4 lefty batters--Ortiz, Shaw, Holt, and Bradley. Of the remaining five lineup slots, all righties, four are in the top five slots--leading off with Betts, Pedroia, and Bogaerts with Ramirez betting right behind Ortiz in the 5th slot. In other words, this Sox lineup practically demands a righty starter--except of course that all of our righty regulars hit righties better than lefties.