Top Tools: Best Fastball/Curveball

Scouts spend countless hours watching and evaluating players, carefully considering the appropriate grade for each tool or each pitch a player offers. Throughout the course of the season and particularly throughout the course of ranking season, grades are tossed around with near reckless abandon. This player has plus power, and that player has a below-average fastball. This player offers above-average hit projection while that player buries hitters with a potential plus-plus curveball. It's easy to talk about the quality of an individual tool, but what does it all mean in the context of other players?

In the second edition of the annual Top Tools Series, the Baseball Prospectus Prospect Staff debated long and hard over how individual players’ tools stack up against those of their counterparts. Drawing upon our own eyewitness accounts and opinions from scouts across the league, the team debated and compiled the following ratings. The end result is a product that captures the oft-missing context of how individual player tools compare and who has the best of each tool in baseball.

Previous entries: Best Hit/Power | Best Speed/Makeup | Best Infield Defense/Infield Arm | Best Outfield Defense/Outfield Arm | Best Catcher Defense/Catcher Arm

Fastball

Top Fastball in the Minor Leagues: Yordano Ventura (Kansas City Royals)
The raw velocity Ventura possesses can stand with that of any pitcher in baseball, starter or reliever. What separates Ventura is his ability to combine movement with extraordinary velocity while also maintaining that velocity deep into games. Ventura’s arm speed borders on the absurd and helps him generate elite velocity from a small, thin frame. Over the last two years, he has dramatically improved his ability to manipulate the movement on his fastball, cutting and sinking the pitch in a variety of velocity ranges. Ventura is surprisingly strong for his size and continues to generate easy cheese no matter how deep he works into the game, giving him the full suite of characteristics associated with a premium fastball.

Others Considered: Kyle Crick (San Francisco Giants), Mike Foltynewicz (Houston Astros), Lucas Giolito (Washington Nationals), Jonathan Gray (Colorado Rockies), Keury Mella (San Francisco Giants), Alex Meyer (Minnesota Twins), Fracellis Montas (Chicago White Sox)
The Giants have had a knack for developing high-octane arms in recent years, and both Crick and Mella should continue that tradition. Crick’s fastball currently plays in the 94-97 range and touches near triple digits, and scouts frequently project that he could sit at 97-99 mph in short bursts. Mella already has plenty of velocity, sitting in the mid-90s, and at just 20 years old with a projectable frame, he could park in the upper 90s consistently over the next couple of years. The Astros have seen Foltynewicz make the leap from a guy who sat in the low- to mid-90s to a guy capable of working in the upper 90s and touching 100 mph in most of his starts. He velocity still fluctuates from time to time, but his consistency improved throughout the 2013 season and he is poised to make his mark with one of the elite fastballs in baseball. Gray, Giolito, and Meyer can all pump mid-90s gas while regularly touching 97-98 mph throughout their starts, and Giolito has the potential to surpass that range as he continues to get further away from Tommy John surgery.

Top Major League Fastball: Aroldis Chapman (Cincinnati Reds)

All-Time Tool: Aroldis Chapman

How to Identify It: Arriving at a fastball grade is one of the simpler thought processes of all the tools, because it is more of a measurement than a judgment. As opposed to the rest of the pitching tools, velocity plays an overwhelming role in the process, with a radar gun being the instrument of choice in determining a pitcher's velocity. The standard scouting scale for velocity is as follows:

A pitcher's initial fastball grade is derived from where he regularly finds himself on the radar gun, or "sits" throughout the outing. The peak velocity is not used but could be a sign of things to come in the future. The chart doesn't differentiate between whether a pitcher is left- or right-handed, but handedness will often be noted due to the scarcity of hard-throwing lefties. A pitcher's future fastball grade could be higher on the 20-80 scale than his present grade if there's projection in the player. This could be physical projection, as a young athletic hurler could find himself throwing harder once he's able to tack on additional strength and fill out his frame. Another factor could be the player development team, which might improve and solve issues in a delivery, such as by incorporating the lower body and legs for a player who is all upper body.

While the number that appears on the radar gun has much to do with the grade, it's not an exact science. This is where the judgment factors in, as evaluators may change a fastball grade depending on its life or lack of life. An upper-90s fastball is an 80-grade offering but could be moved down to a 70 or 75 if the pitch is true and flat. Control is also an important factor in the grading process, as some evaluators put a higher importance on where a pitcher "sits" for strikes as opposed to all pitches, which could decrease a pitcher's grade. —Ronit Shah

Curveball

Top Curveball in the Minor Leagues: Archie Bradley (Arizona Diamondbacks)
Featuring a knuckle-curve that can buckle knees, Bradley’s hammer has few true competitors in the minor leagues. Thrown with serious conviction, Bradley generates atypical velocity with his curveball, helping to make the bite and vertical movement even more dramatic. He has demonstrated an ability to move the pitch around, finishing it in the strike zone and working it out of the zone as a chase pitch. With frequent plus-plus grades, Bradley uses the curveball to back up his overpowering fastball, leaving him with a dominant one-two punch at the front of his arsenal.

Others Considered: Hunter Harvey (Baltimore Orioles), Lance McCullers (Houston Astros), Jameson Taillon (Pittsburgh Pirates), Zack Wheeler (New York Mets), Kyle Zimmer (Kansas City Royals)
Last year’s leader in the clubhouse, Taillon still has a big-time hammer, but the progress Bradley made in 2013 couldn’t be ignored. Wheeler and Zimmer both rate highly as well, and they earned plenty of support from scouts, but the consensus indicated that they were a half tick behind Taillon and Bradley. McCullers had one of the best curveballs in the 2012 draft and the pitch showed more consistency throughout his full-season debut last year. Harvey is a new entrant to the mix and could establish his breaking ball as one of the premier pitches in the minor leagues with a strong showing in 2014.

Top Major League Curveball: Clayton Kershaw (Los Angeles Dodgers)

All-Time Tool: Nolan Ryan

How to Identify It: The curveball is the more traditional, but now less used, of the breaking pitches. It's a vertical breaking pitch, but it can come in many shapes and velocities. Although it varies based on the arm angle, the curve will usually not have a lot of horizontal movement. A 12-6 or 11-6 rotation (referring to movement superimposed on the face of a clock) is ideal for a right-handed pitcher; 1- or 2-6 shapes are ideal for lefties, who tend to have lower arm slots. A lower arm angle or the hand not being on top of the ball can cause the pitch to lose definition and become “slurvy.”

A curveball is thrown similarly to a football at release. The grip is usually held on one half of the ball with the middle finger resting against the side of the horseshoe on the seams of the ball. At release, the fingers should be on top of the ball so that they can pull down through the ball, creating the sharp downward movement that you want. The shape of the pitch may be loopier/bigger or may “fall off the table.” Loopier curveballs are slower with more depth and up-and-down movement, while still staying tight throughout. They can become “lazy” when they lose the sharpness and are picked up earlier out of hand. Harder curveballs will not have as big a shape but will stay on plane with less upward movement, then dive suddenly just before reaching the plate. The best curveballs overall will have late, sharp movement, making balls become strikes and strikes become chase pitches. —Steffan Segui

Article discussed and debated by the Baseball Prospectus Prospect Staff. Constructed and delivered by Mark Anderson.