What makes Twins outfielder Byron Buxton the No. 1 prospect in baseball? He doesn't have one signature tool that stands out above his others. Rather, Buxton has four superlative tools that grade as 70s or better on the 20-80 scouting scale, while his power rates as a 60.
We break down the best tools among MLB.com's Top 100 Prospects below. While Buxton didn't claim superiority in any one category, he ranked second in terms of hitting ability, speed and defense, and third in arm strength. The only other position player to get mentioned more than once was Rangers third baseman Joey Gallo, who has plenty of power in his bat and his arm.
On the pitching side, Rockies right-hander Jonathan Gray laid claim to ownership of the best fastball and best slider among the Top 100 Prospects. Righties Eddie Butler (Rockies), Kevin Gausman (Orioles), Lucas Giolito (Nationals) and Marcus Stroman (Blue Jays) -- all products of the 2012 First-Year Player Draft, as were Buxton and Gallo -- earned recognition in multiple categories.
Best hitter: Oscar Taveras, OF, Cardinals
There's a reason Taveras keeps getting linked to Albert Pujols, even if he does hit left-handed. Taveras' Minor League resume includes a .320/.377/.518 stat line, one Double-A Texas League MVP Award, two batting titles and three league championships. No prospect barrels balls or makes hard contact as consistently as Taveras, who projects to hit .300 or better with 25-homer power in his prime as a Major Leaguer.
Also in the running: Buxton; Nick Castellanos, 3B, Tigers; Garin Cecchini, 3B, Red Sox
Best power: Miguel Sano, 3B, Twins
Since Minnesota handed him a $3.15 million bonus in October 2009, Sano has slammed 90 homers in 379 pro games, including 28 to top the Class A Midwest League as a 19-year-old in 2012 and 35 between Class A Advanced and Double-A last season. The 6-foot-4, 235-pounder generates his tremendous pop to all fields with a combination of lightning bat speed and prodigious strength. He also demonstrates some patience at the plate, helping him to tap into his power.
Also in the running: Gallo; Javier Baez, SS, Cubs; Kris Bryant, 3B, Cubs
Fastest runner: Billy Hamilton, OF, Reds
Given the way Hamilton's speed plays on the diamond, it really merits a 90 on the 20-80 scouting scale. He broke Vince Coleman's professional baseball record with 155 steals in 2012, and he swiped 13 bases in 14 attempts for the Reds last September -- despite getting just 19 at-bats. One scout called Hamilton, a former Mississippi State wide receiver recruit, the fastest player to come out of Mississippi since former Negro Leagues star and Hall of Famer Cool Papa Bell.
Also in the running: Buxton; Delino DeShields Jr., OF, Astros; Gregory Polanco, OF, Pirates
Strongest arm: Jorge Alfaro, C, Rangers
Signed for a Colombian-record $1.3 million in January 2010, Alfaro has the highest ceiling of any catching prospect. Both his power and his arm strength are well-above-average tools, and scouts rate his arm a full grade better than his pop. Regularly turning in pop times of 1.8 seconds on throws to second base, Alfaro ranked second in both the Class A South Atlantic League (36 percent) and Arizona Fall League (50 percent) in throwing out would-be basestealers last year.
Also in the running: Gallo; Buxton; Carlos Correa, SS, Astros
Best defender: Jackie Bradley Jr., OF, Red Sox
Though his speed grades as solid at best, Bradley Jr. has an innate ability to read balls off the bat that allows him to chase down balls from gap to gap in center field. His defensive prowess helped spur South Carolina to consecutive College World Series championships in 2010-11, and it enabled him to make Boston's Opening Day roster last year at age 22. The Red Sox may miss Jacoby Ellsbury's bat this season, but Bradley Jr. will be a defensive upgrade over the $153 million free agent.
Also in the running: Buxton; Albert Almora, OF, Cubs; Francisco Lindor, SS, Indians; Austin Hedges, C, Padres
Best fastball: Gray
Gray's fastball topped out at 94 mph and got him drafted by the Royals in the 13th round out of Chandler (Okla.) High in 2010, and by the Yankees in the 10th round out of Eastern Oklahoma State Junior College in 2011. It kicked into another gear last year, sitting in the mid-90s late into games, reaching triple digits and featuring extremely heavy life. That's one reason the Rockies drafted Gray third overall and signed him for $4.8 million -- and we'll get to another in a moment.
Also in the running: Giolito; Mike Foltynewicz, RHP, Astros; Butler
Best curveball: Robert Stephenson, RHP, Reds
Stephenson can run his fastball up to 99 mph, but when he's on top of his curveball, it can be just as devastating. He throws his curve with power at 77-83 mph and with sharp 12-to-6 break. Even better, Stephenson shows the aptitude for both throwing his bender for strikes and enticing hitters to chase it out of the zone.
Also in the running: Kyle Zimmer, RHP, Royals; Archie Bradley, RHP, Diamondbacks; Giolito
Best slider: Gray
Scouts won't go so far as to claim that Gray's breaking ball is the equal of his fastball, because his heater grades as an 80. However, his slider also has improved dramatically and now rates as a well-above-average offering. It can lack consistency at times, but Gray often throws it in the upper 80s, with good depth and bite.
Also in the running: Stroman; Alex Meyer, RHP, Twins; Butler
Best changeup: Gausman
Gausman had little need for a changeup in high school before adding a quality one during his two seasons at Louisiana State, helping him become the first college pitcher taken in the 2012 Draft. He usually uses a split/changeup that arrives in the mid-80s, about 10 mph slower than his fastball, and dives at the plate. Gausman's changeup helped him rush to the big leagues last May, and it was his most effective pitch once he got there.
Also in the running: Dylan Bundy, RHP, Orioles; Henry Owens, LHP, Red Sox; Justin Nicolino, LHP, Marlins
Best control: Noah Syndergaard, RHP, Mets
Among pitching prospects, no one can match Syndergaard's ability to deliver quality stuff, throw strikes and miss bats. Not only can he unleash a mid-90s fastball, hard curve or a promising changeup, but he also can locate them where he wants. Syndergaard posted the best strikeout (11.5 per nine innings) and walk (2.0) rates of his career after he reached Double-A last June.
Also in the running: Edwin Escobar, LHP, Giants; Gausman; Stroman
Jim Callis is a reporter for MLB.com and writes a blog, Callis' Corner. Follow @jimcallisMLB on Twitter.