McAdam: Red Sox assistant GM Zack Scott details the thinking behind Mookie Betts' lineup move

The 2019 Red Sox will look very much like the 2018 Red Sox.

The rotation returns intact from a year ago, and so does the starting lineup. If you count first base as a platoon spot, the Red Sox will have the same 10 players on a daily basis that they had a year ago -- allowing for the projected return of Dustin Pedroia, who participated in just three games in 2018.

The one change evident will come in the batting order. Last month at the winter meetings, Alex Cora revealed that he intends to flip Mookie Betts and Andrew Benintendi in the order, with Betts dropping down to second and Benintendi elevated to the top spot.

But even that shouldn't be a radical change.

When Cora first began contemplating the switch, he sought input from Zack Scott, the Red Sox' senior vice president/assistant general manager who handles much of the advanced metrics in the club's Baseball Operations department.

Scott thought about it for a minute and agreed it made sense.

"When you have a guy (like Betts) who can knock in runs,'' said Scott, "often times, the leadoff guy - especially when the No. 8 and No. 9 guys were struggling last year -- won't get that many RBI opportunities. You weren't maximizing those opportunities. So this is a chance to give him a little more of those while still keeping him as a table-setter.''

Indeed, while Betts won the American League MVP in November for his standout season, his RBI total (80) was a relatively modest one, especially considering his 84 extra-base hits. Had Betts hit a little lower in the lineup, those extra-base hits would have delivered many more runs.

As it was, by virtue of his spot as the leadoff man coupled with the struggles of Red Sox catchers (who often hit eighth) and, in the first half of the season, Jackie Bradley Jr. (ninth) Betts's at-bats led off an inning 211 times, or, 41 percent of his at-bats.

That resulted  in far fewer chances to knock in runs. Of his 32 homers, 23 came with the bases empty -- again, costing the Sox scoring opportunities.

When Cora first interviewed for the managerial opening with the Red Sox, it was with the notion that Betts would be his leadoff hitter with Benintendi right behind. He modeled it after what his previous employer, the Houston Astros, had done by utilizing George Springer as his leadoff man.

"The idea,'' said Scott, "was to put the (opposing) pitcher in a tough battle as soon as possible and get those guys as many at-bats as possible.''

So when Cora contemplated a changeup, it was with the idea of merely flipping the two.

"They're both good on-base guys,'' Scott noted, "and one (Betts) has, so far, proven to be a better power guy.''

Scott emphasized that fixation over lineup construction can go too far and stressed that, taken as one move, the switch of Betts and Benintendi isn't a major shakeup.

"Every move you make has a corresponding effect on the rest of the lineup,'' he said. "The net gains you get are so small and only because baseball is a long season can you get any (gains) squeezed out of it.''

And every proposed change with the lineup has its plusses and negatives. As an example, Scott pointed to the debate last season over whether J.D. Martinez should hit third or fourth. By hitting him third, you're guaranteed to get Martinez up in the first inning every game. But, he added, no spot in the lineup results in more at-bats with no runners on base and two outs than the No. 3 spot.

On the other hand, by dropping him to cleanup, you're costing Martinez at-bats.

"There's always a cost that comes with it,'' Scott said. "And usually, there's more discussion about (moves) than is actually worth it.''

There's little doubt that Benintendi fits the modern profile of a leadoff hitter, with the ability to provide extra-base sock (42 doubles) and on-base ability (.366 OBP in 2018).

Meanwhile, dropping Betts to second should also help the outfielder regain some of his aggressiveness at the plate. When Cora met with Betts last winter to discuss his installation as leadoff hitter, Betts thought he was getting a mixed message when the manager stressed that he wanted Betts to be aggressive in the top spot.

For much of the year, Betts followed instructions. But there were times -- in September and for much of the postseason -- where Betts reverted to a more passive approach, putting himself in pitcher's counts and not taking advantage of strikes thrown to him.

Moving him to second, the Sox theorize, will perhaps allow him to maintain his aggressiveness more consistently.

"I don't know if batting leadoff had anything to do with (the occasional passivity),'' said Scott. "But maybe (being out of the leadoff spot) mentally frees him up.''

Overall, Scott doesn't expect a huge change in the team's production.

"It's such a small tweak,'' said Scott. "The reality of it is -- and I don't want speak for Alex -- it's hard to believe it's really going to make a big difference either way. It's just kind of re-arranging things to maybe squeeze some extra RBI opportunities for Mookie and we're flipping him with a guy in Andrew who can still get on base at a high rate. I don't see it doing a lot either way.

"When Alex suggested it, I was like, 'Yeah, either way.' It's just not a needle-mover.''