This season, Daniel Nava was a revelation for the Boston Red Sox. The undrafted refugee from the independent leagues earned regular work and finished with the third-best OPS among all the Sox with at least 250 plate appearances. And this was a good team that led the American League in scoring!
Nava's a switch-hitter, and started 100 of the 108 games started by enemy right-handed pitchers. Which made a lot of sense, because in the majors he's been much better against righties than lefties: 833 OPS vs. the former, just 634 against the latter.
Meanwhile, Jonny Gomes, a right-handed hitter, started 22 games against right-handed pitchers all season. Gomes did start all 54 games started by enemy southpaws. Essentially, he was a platoon player. More so than Nava, who started 34 games against lefties (but maybe shouldn't have, considering his career numbers against them).
All of which is a roundabout way of saying that John Farrell had a nice arrangement in left field this season. He had Shane Victorino holding down right field, Jacoby Ellsbury in center field, and a lovely Nava/Gomes platoon in left field. In that order, since there are a lot more right-handed than left-handed starting pitchers.
And now, at the most important time of the whole year, Farrell's tossed that nifty platoon into the wastebin.
Nava started the third and fourth games of the Red Sox' Division Series against the Rays, and went 1 for 5 with a couple of walks. He started the first game of the ALCS against the Tigers, and went 1 for 3 with a walk ... and that's the last we've seen of him, even though the Tigers don't have anything but right-handed starting pitchers.
Meanwhile, Gomes has played left field in Games 2 and 3 against the Tigers. His personal results: 2 for 7 with five strikeouts, and both hits were seeing-eye grounders that didn't escape the infield.
And yet ... if you asked John Farrell about Jonny Gomes, even if you asked John Farrell about Jonny Gomes after injecting a healthy dose of truth serum, I'll bet he would tell you the move has worked. After all, the Red Sox won both games by one run. In Game 2, Gomes' ninth-inning (infield) single started the game-winning rally. In Game 3, he made this catch ...
... which sounded a lot more spectacular on the radio than it looks there. Still, Nava is almost certainly a below-average left fielder, and might well have not made that play. Which makes it very easy for John Farrell to argue, even with the sodium pentathol, that he's now won two games with Jonny Gomes in the lineup that he might well have lost without him.
Fine. Now Farrell's playing with the house's money. And like every smart gambler, he really should quite while he's ahead. The Red Sox still need to win two more games against the Tigers. If that happens, they have to take four from a really good National League team.
If the Red Sox wind up facing the Dodgers, Farrell should be able to naturally satisfy his odd Jonny Gomes fetish, because the Dodgers have two lefty starters. But in the more likely event that the Sox face the Cardinals and their all-righty rotation, Farrell really needs to quit playing hunches and start playing the percentages. That worked pretty well for six months.