The Most Improved Players Thus Far by Projected WAR

What follows represents an attempt by the author to utilize the projections available at the site to identify the five major-league hitters whose WAR projections have most improved on a rate basis since the beginning of the season.

For every batter, what I’ve done is first to calculate his preseason (PRE) WAR projection per every 550 plate appearances (or 415 for catchers), averaging together Steamer and ZiPS forecasts where both are available. What I’ve done next is to calculate every hitter’s rest-of-season (ROS) WAR projection (again, prorated to 550 PA and using both Steamer and ZiPS when available). I’ve then found the difference in WAR per 550 PA between the preseason and rest-of-season projection.

Only those hitters have been considered who both (a) are currently on a major-league roster and (b) have recorded 100-plus plate appearances and (c) weren’t accidentally omitted by the author, who is a moron. Note that PRE denotes the player’s preseason projection; ROS, the rest-of-season projection; and Diff, the difference between the two. Note also that all figures are expressed as prorated projections (per 550 PA for field players and 415 PA for catchers). Data is current as of Monday.

5. Seth Smith, OF, San Diego (Profile)

Notes
When Smith appeared on a similar list to this one at the beginning of July, his combined rest-of-season projection called for him to produce a 118 wRC+ and 2.0 WAR per every 550 plate appearance — a considerable improvement, that, over his preseason forecasts. Now, a month-plus later, he’s projected to produce a 125 wRC+ and 2.4 WAR per every 550 plate appearances — in other words, even better figures. While extending Smith might have been weird, that probably has more to do with the Padres specific circumstances and not Smith’s own ability.

4. Emilio Bonifacio, UT, Atlanta (Profile)

Notes
More than the other four players to appear here, Bonifacio’s improved projections are largely a product of defensive metrics. Between 2011 and -13 — which is to say, a not entirely unreasonable sample for defensive metrics — Bonifacio was worth about -9 runs defensively overall, accounting both for positional adjustment and runs saved (or not) per UZR. This season, Bonifacio has saved 8 or 6 runs according to UZR and DRS, respectively, while receiving a positional adjustment of +1.0 by virtue of playing mostly second base and center field. One can see the likely effects of this recent performance in Bonifacio’s current projections. After producing a combined defensive projection of about -8 runs overall over a whole season for Bonifacio, Steamer and ZiPS now project about a +2 or +3 figure for him — average, that, for a second baseman or center fielder.

3. Kevin Kiermaier, OF, Tampa Bay (Profile)

Notes
In most ways, Kiermaier’s preseason and rest-of-season offensive rate projections resemble each other pretty strongly. Walk and strikeout rate: about the same. Batting average on balls in play: nearly identical. Overall batting average and on-base percentage: again, similar. His projected home-run rate, on the other hand: different. In 1,649 plate appearances across basically every level of the minors, Kiermaier hit 15 home runs. In 236 plate appearances with Tampa Bay just this season, however, the 24-year-old has hit nine of them (i.e. home runs). Projected originally to produce a .099 ISO, Kiermaier has instead recorded a .228 ISO mark. The influence of that newest data is visible in his improved ISO projections — about 36 points higher, those, than that aforementioned preseason mark.

2. Steve Pearce, 1B/OF, Baltimore (Profile)

Notes
No member of the Baltimore Orioles — not even Nelson Cruz, what with his league-leading 31 home runs — has produced a park-adjusted batting line as high as Pearce’s 136 wRC+. Moreover, he’s tied for second on that same club with J.J. Hardy in wins above replacement despite having too few plate appearances to qualify. The discerning reader will note that Pearce’s rest-of-season batting projection has actually declined since the last iteration of this exercise, from 121 wRC+ to 119 wRC+. Either figure represents a considerable improvement, however, over his preseason numbers.

1. David Peralta, OF, Arizona (Profile)

Notes
A brief inspection around Peralta’s player page reveals pretty quickly that he’s the product of unusual circumstances. Regard, by way of illustration, this embiggenable image:

One finds a couple years of pretty competent offensive performance from an old prospect and then, prior to that, two non-seasons from a teenage Cardinals prospect in the middle of the aughts. The reason: Peralta, a native of Venezuela, was a pitcher in those Cardinals season. And then he wasn’t one. And then he was — like four years later, that is — he was an outfielder in no fewer than two independent leagues. Signed by the D-backs last summer out of one of those independent leagues, he’s now probably the most improved player in all of baseball by WAR.