The New York Mets had grandiose visions for Mike Pelfrey when the organization selected him 9th overall in the 2005 Amateur Draft. A lanky, 6-7 righthander from Wichita State, Pelfrey was pegged as a major league-ready talent who only lasted until the 9th pick because of Scott Boras-induced bonus demands. Equipped with a "projectable" pitcher's frame as well as a plus fastball with sink and run, the former Shocker was expected to develop into an ace in short order.

Problem was, the scouting report on Pelfrey entering the 2008 campaign read entirely like the pre-draft 2005 report: an enticing sinker, but little in the way of secondary offerings. Pelfrey scrapped his curveball in favor of a slider, but neither breaking ball showed much promise and his changeup was rarely utilized. A one-trick pitcher, Pelfrey produced middling results with the Mets in 2006 and 2007:

'06: 21.1 IP, 5.49 ERA, 5.54 K/9, 5.11 BB/9, 54 GB%

'07: 72.2 IP, 5.57 ERA, 5.61 K/9, 4.86 BB/9, 49 GB%

2008 also started out inauspiciously for Pelfrey, as he slogged through the first two months of the season with middling peripherals. However, since the calender turned to June, Pelfrey has performed considerably better...

April/May: 56 IP, 4.98 ERA, 4.66 K/9, 4.01 BB/9, 1.35 GB/FB

June/July: 52.2 IP, 2.24 ERA, 6.03 K/9, 3.10 BB/9, 2.46 GB/FB

His peripherals aren't top shelf, mind you, but he's whiffing almost a batter and a half per 9 more while walking almost one less, while also inducing a ton of grounders.

In other words, everything is trending up for Pelfrey. Is his improvement simply a sample-size mirage, or is his performance predicated on changes in his pitch selection and quality? To find out, I am going to examine Pelfrey's Pitch F/X data, splitting the data into two groups: Bad Pelfrey (April/May) and Good Pelfrey (June/July), comparing the two to see any noted changes in pitch caliber and repertoire. If Pelfrey is indeed doing something different over the past two months, perhaps his improvement is legitimate, indicative of a matured pitcher better utilizing his talents. Conversely, if the two sets appear the same, perhaps he's just going through an aberrant stretch and is destined to return to his previous level of performance.

Bad Pelfrey (April/May)

The chart shows the vertical and horizontal movement (in inches) that Pelfrey got on his pitches, relative to a pitch thrown without spin. The X axis shows the amount of horizontal movement on Pelfrey's pitches, while the Y axis shows the amount of vertical movement on the pitches. The chart is from the view of the catcher, so pitches with a negative horizontal (X axis) value are tailing in on a righthanded hitter. Pitches with a low vertical (Y axis) value are moving down in the strike zone; the lower the Y value, the more downward movement the pitch has.

Pitch MPH X(In.) Z(In.) %Thrown

FB 92.73 -8.75 8.54 77.5

SL 84.67 -0.36 4.35 16.6

CH 83.16 -9.92 5.39 5.9

Type is the type of pitch thrown. FB=Fastball, SL=Slider, CH=Changeup. MPH is the average initial velocity of the pitch. X is the amount of horizontal movement on the pitch. Remember, a negative X value means the pitch is moving toward a righthanded batter. Z is the amount of vertical movement on the pitch. The lower the Z value, the more downward movement on the pitch. %Thrown is the percentage that Pelfrey threw each pitch.

Pelfrey is obviously a fastball-first pitcher, and that trend was still evident in April and May. The 6-7 righty threw his heater 77.5% of the time, at an average velocity of 92.73 MPH. Pelfrey got plenty of arm-side run on the pitch (-8.75 X), tailing the fastball in on righties. For comparison, the average fastball gets about -5.46 inches of horizontal break.

The slider was Pelfrey's most used secondary offering (16.6%). The pitch left something to be desired, as it possessed neither great horizontal movement away from rightanded batters ( at -0.36 X, it was actually slightly in on righties) or downward tilt (4.35 Z). This has long been Pelfrey's bane: impressive as his fastball is (and it's a plus offering), his breaking ball had just been a "show-me" pitch.

Pelfrey's changeup was another modest offering in the early months of the season. The difference in velocity between his heater and his change was average (9.57 MPH), and the pitch featured a little bit of "fading" action away from lefties (-9.92 X, compared to -8.75 X for the fastball). The vertical difference between the fastball and changeup was also nothing special (5.39 Z on change; 8.54 Z on fastball). Perhaps realizing the average-ness of the pitch, Pelfrey only used his change 5.9% of the time.

Pelfrey's April and May looked largely like what we have seen from him over the past few seasons: A good fastball with plenty of tailing action, but a slurvy breaking ball that catches the plate and a shoulder shrug-inducing change.

Good Pelfrey (June/July)

Pitch MPH X(In.) Z(In.) %Thrown

FB 93.9 -8.09 7.08 84.4

SL 85.41 0.74 3.89 9.9

CH 84.17 -9.14 5.33 4.4

CB 74.41 3.71 -2.63 1.3

(CB=Curveball)

So, what does Pelfrey (who some would say relies too much on his heater) do during the best stretch of his professional career? He throws more heaters, of course. Already heavily reliant on his fastball over the first two months, Pelfrey actually increased his percentage of cheese 6.9%, from 77.5% to 84.4%. He's also throwing the pitch harder as of late, with an average fastball velocity of 93.9 MPH (a 1.17 MPH increase). With that increase in speed has come a reduction in horizontal movement (-8.09 X in June/July, compared to -8.75 X in April/May). It appears as though Pelfrey has made a decision to increase the velocity on his heater at the expense of some movement. This would appear to be a worthwhile swap: the pitch still has plenty of tailing action and now batters have even less reaction time to put the bat on the ball.

Pelfrey's slider has shown slight improvement over his hot streak. He's throwing the pitch a bit harder (85.41 MPH), with greater horizontal movement away from righties (0.74 X) and better tilt (3.89 X). No one will ever confuse his slider with Brad Lidge's, but Pelfrey's recent incarnation of the pitch is at least a step in the right direction. Despite the seeming gains, Pelfrey has utilized the pitch less often in June/July (9.9%).

Little has changed regarding Pelfrey's changeup; it's still just sort of there. Perhaps not concidentally, the already scarcely-used pitch has seen a slight reduction in appearance (4.4%).

Well, look at that- the curveball has returned from the dead. He hasn't thrown the pitch terribly often, mind you, but Pelfrey is beginning to re-introduce the pitch into his repertoire: 1 yellow hammer in his June 27th start against the Yankees, and five apiece over his last two starts against the Giants and Rockies. Pelfrey will likely always rely predominantly on his fastball, but it can't hurt to give batters another pitch to think about.

In conclusion, "Good Pelfrey" has made several changes from "Bad Pelfrey":

- Increased fastball usage, trading some movement for velocity

- Modest improvement on the slider

- Re-introduction of the previously scrapped curveball

Whether these recent trends continue remains to be seen, but Pelfrey appears to have made a few alterations to his pitching style over the past two months that bode well for his long-term development. With Pedro Martinez's achy shoulder, Oliver Perez's erratic nature and John Maine's occasional hiccups, the Mets surely could use the more recent version of Mike Pelfrey, the one the team envisioned upon drafting him three years ago.

David Golebiewski is a contributing writer for Driveline Mechanics and The Transaction Guy on the MVN Network. Contact David at david@drivelinemechanics.com