Jim Salisbury tweeted this earlier and I figured it is worth explaining why this is a good thing:
Asked R. Amaro if he'd consider Rollins for 3b nxt yr w Galvis at SS. "No. He's our SS." That's that. #Philliestalk
— Jim Salisbury (@JSalisburyNBCS) August 2, 2012
Fans have become very fond of the 22-year-old Freddy Galvis for his defensive prowess and max-effort plays despite his lacking production at the plate (.266 wOBA). He was never much with the bat, but took a big leap last year between Double-A Reading and Triple-A Lehigh Valley, finishing with an aggregate .716 OPS between the two levels. That mark vastly exceeded his previous career-high OPS of .588.
As offense declined around the league over the past few years and the importance of pitching and defense subsequently increased, there’s a lot more tolerance for an offensively-light, defensively-sound player like Galvis. Offense is at its lowest since 1992, a time when Ozzie Smith, a 15-time All-Star and owner of a career .666 OPS, was among the most popular and respected players in baseball.
If the Phillies were to shift Jimmy Rollins over to third base and put Galvis at shortstop, however, they would be losing a lot on both ends. For one, Galvis isn’t demonstrably better than Rollins defensively. The sample sizes are much too small to cite any stats — and even if you did, there’s not a clear favorite — but while Galvis might have the edge in speed and range, Rollins has his own advantages in positioning (like his double play partner Chase Utley) and decision-making. When you consider how much better Rollins is offensively (.319 wOBA) and on the bases (17-for-21; Galvis didn’t attempt any steals in 200 PA), Galvis would have to be the defensive equivalent of Adrian Gonzalez to Rollins’ Prince Fielder. And even then, it wouldn’t be worth it.
Then think about what the Phillies would miss out on by moving Rollins to third base. The average shortstop has posted a .298 wOBA while a third baseman has put up a .316 wOBA. By converting wOBA to runs…
( ( Rollins’ wOBA – Positional Average wOBA ) / 1.15 ) * 600
…we see that the difference between the two positions, over 600 plate appearances, is about ten runs or a full win. The difference between Rollins’ .319 wOBA relative to the positional average is +11 runs at shortstop and +1.5 runs at third base. There’s also the question of whether Rollins’ defense would be comparably as good at the hot corner, which likely wouldn’t be the case since he’s spent exactly zero defensive innings at third base in his entire professional career dating back to 1996 when he was a 17-year-old in the Appalachian League.
The net gain for the Phillies would have to be well in excess of ten runs above replacement at shortstop above what Galvis would have to do to match Rollins, something Galvis realistically could only do defensively. Considering that Rollins is at 3 fWAR as a 33-year-old near the end of his career, it’s statistically improbable that Galvis would provide the Phillies an upgrade not just at shortstop, but at any position. His bat is just too bad and his defense, while great, isn’t anywhere close to good enough to make up for the difference.