Since nearly the first day of the season, each player page at FanGraphs has featured — in addition to the assortment of 2014 projections made available during the preseason — both a rest-of-season and updated end-of-season projection for both the Steamer and ZiPS systems. In what follows, the author has utilized that data to the end of identifying five pitchers whose end-of-season projections have most improved since the beginning of the season.

Depending on what question one is specifically hoping to answer, there are a number of ways to attempt such an endeavor. What follows is the methodology I’ve used, however, with a brief explanation of certain choices.

What I’ve done is to:

1. Find the preseason projections for each pitcher according both to Steamer and ZiPS.

2. Re-calculate each pitcher’s preseaon ZiPS WAR based on FanGraphs’ preseason depth-chart innings projection (see note below for explanation).

3. Find the average of each system’s preseason WAR projection for every pitcher (using the re-calculated ZiPS WAR figure).

4. Find the updated projections for each pitcher according both to Steamer and ZiPS.

5. Calculate each pitcher’s updated ZiPS WAR, as well, based on FanGraphs’ depth-chart innings projection.

6. Find the average of each system’s updated WAR projection for every pitcher (using the re-scaled ZiPS figure).

7. Subtract the composite preseason WAR projection from the composite updated WAR projection.

8. Identify the top-five pitchers by this measure.

9. Write a dumb post about it at FanGraphs.com.

The impetus for re-calculating the ZiPS WAR figures has nothing to do with any sort of shortcoming associated with ZiPS, but rather with how that particular system issues a playing-time projection based largely on playing time from recent seasons — as opposed, that is, to the unqiue circumstances facing each player within the context of his team. Steamer, on the other hand, uses playing-time estimates as taken from FanGraphs’ depth charts — which estimates (ideally) offer a more accurate sense of how a player will be used within the context of his organization.

What follows are the five pitchers whose end-of-season WAR projections have most improved since the beginning of the season. Projection denotes a composite Steamer and ZiPS projection. PRE denotes the player’s preseason projection; UPD, the updated projection. All figures are current as of some time in the middle of the night between Tuesday and Wednesday.

5. Michael Wacha, RHP, St. Louis (Profile)

Projection (PRE): 173 IP, 8.0 K/9, 2.7 BB/9, 0.91 HR/9, 3.56 FIP, 1.9 WAR

Projection (UPD): 177 IP, 8.3 K/9, 2.3 BB/9, 0.85 HR/9, 3.31 FIP, 2.8 WAR

Notes

Despite his success at the end of last season and then throughout the Cardinals’ postseason run, there was some concern regarding Wacha due to the limited nature of his repertoire — which repertoire featured an effective fastball and effective changeup, but little else. Wacha has begun the 2014 season by throwing his curveball more than twice as often; he’s also begun it by producing a 75 xFIP- (i.e. a really good xFIP-) over four starts and 26.0 innings. Whether the latter fact is influenced by the former isn’t immediately clear, however: one notes that the Wacha has used the curve much less often as a strikeout pitch (which is smart, because it’s produced only a 4.4% swinging-strike rate) than he has to generate first-pitch strikes against right-handed batters. Such usage suggests that the curve has been helpful, perhaps, but not useful as another outpitch.

4. Chris Archer, RHP, Tampa Bay (Profile)

Projection (PRE): 163 IP, 7.7 K/9, 3.7 BB/9, 0.94 HR/9, 4.11 FIP, 1.4 WAR

Projection (UPD): 177 IP, 7.7 K/9, 3.3 BB/9, 0.74 HR/9, 3.65 FIP, 2.3 WAR

Notes

Over 150-plus innings between 2012 and -13 — almost all of them in a starting capacity — Archer recorded a strikeout rate of 21.2%. Over 24.2 innings this season — definitely all of them as a starter — Archer has recorded a strikeout rate of 20.8%. Very slightly less, is how that compares to his established level from the previous two seasons. Generally, pitchers aren’t issued more promising projections when their strikeout rates demonstrate little (or no) movement upwards. In Archer’s case, the improvement is tied both to an improving walk rate and also to how he’s conceded zero home runs thus far after allowing 15 over 128.2 innings in 2013.

3. Drew Hutchison, RHP, Toronto (Profile)

Projection (PRE): 115 IP, 7.5 K/9, 3.4 BB/9, 1.17 HR/9, 4.38 FIP, 1.1 WAR

Projection (UPD): 164 IP, 8.7 K/9, 3.4 BB/9, 1.06 HR/9, 3.94 FIP, 2.0 WAR

Notes

Insofar as he recorded only about 110 innings combined between the 2012 and -13 seasons — those coming on either side of a Tommy John procedure and the subsequent rehab — Hutchison would have posed some difficulties for a projection system entering 2014. An excellent spring, however — during which he finished among the league’s leaders in strikeout rate — suggested that he was prepared, if not to dominate for Toronto, then at least to make a contribution as a starter. The early returns have been excellent in that regard: Hutchison has recorded the 10th-best strikeout rate among 111 qualified starters and 88 xFIP- over his first 20.0 innings.

2. Cliff Lee, LHP, Philadelphia (Profile)

Projection (PRE): 192 IP, 8.7 K/9, 1.5 BB/9, 0.94 HR/9, 3.03 FIP, 3.9 WAR

Projection (UPD): 204 IP, 8.9 K/9, 1.3 BB/9, 0.84 HR/9, 2.73 FIP, 4.8 WAR

Notes

The sort of pitcher one might reasonably expect to find on this sort of list is one who’s either (a) relatively inexperienced or (b) returning from injury or (c) both. That’s the sort of pitcher, for example, who occupies the three entries above the present one. In each case, a system has been compelled to produce a projection based on something less than a full complement of major-league data. The sort of pitcher one doesn’t expect to find on a list such as this one is four-time all-star and former Cy Young winner and perpetually excellent Cliff Lee. Firstly, given the size of the sample and the relative homogeneity of the numbers he’s produced in recent years, Lee really ought to be among the league’s most readily projectable pitchers. Secondly, owing to how excellent he’s been, there’s a lot less room for improvement for Lee than basically every other pitcher. What he’s done so far, however, is to produce walk and ground-ball rates thus far which are superior to any such marks from a previous season — while maintaining the ca. 25% strikeout rate that’s become his established level in recent years.

1. Aaron Harang, RHP, Atlanta (Profile)

Projection (PRE): 10 IP, 6.5 K/9, 3.2 BB/9, 1.39 HR/9, 4.75 FIP, 0.0 WAR

Projection (UPD): 144 IP, 7.4 K/9, 3.4 BB/9, 0.90 HR/9, 3.90 FIP, 1.4 WAR

Notes

The rate stats from Harang’s most recent updated projection aren’t actually quite so good as they appears relative to those from his original preseason one. Harang pitches for Atlanta now, obviously, but his original projection seems to have been issued before he was released by Cleveland — and thus accounts for (more difficult) American League competition. Even if the rates are skewed slightly, the WAR projection for Harang (which is park- and league-adjusted in both cases) has become considerably more optimistic. In his first four starts, Harang has recorded strikeout and walk rates (22.7% and 12.4%, respectively) both notably higher than in previous seasons — an indication, that, which would appear to suggest that he’s throwing less often in the zone (although one not supported by his zone rate, which is roughly the same as in previous seasons).