MLB.com Columnist

Jim Callis

Who's the toolsiest of the Fall (Stars Game)?

Who's the toolsiest of the Fall (Stars Game)?

Before he arrived in Los Angeles ahead of schedule and set a National League rookie record with 39 home runs, Cody Bellinger gave a national television audience a preview of coming attractions last November. Bellinger hit a towering homer in the Arizona Fall League's Fall Stars Game, reinforcing his status as the best power prospect in all of baseball.

At the 2015 Fall Stars Game, Gary Sanchez not only delivered a no-doubt homer but also showed off his arm with a 1.82-second pop time while nabbing a basestealer. Greg Bird blasted a 450-foot long ball in the '14 prospect showcase. Byron Buxton exhibited his tremendous speed with a stolen base in the '13 contest, while Billy Hamilton did the same with a pair of swipes and a diving catch in '12.

When the AFL stages its 12th Fall Stars Game tonight at 8 p.m. ET -- broadcast live on MLB Network and MLB.com -- an impressive array of tools will be on display once again. Here are the best of the best:

Best hitter
Luis Urias, SS/2B, Padres

After winning the high Class A California League batting title (.330) at age 19, Urias encored by batting .296 in Double-A at age 20 and topping the Texas League in on-base percentage (.398). He has advanced feel for the barrel as well as the strike zone, and he has hit at least .296 and walked more than he has struck out in each of his four pro seasons. Urias is batting .355 with nine walks and three whiffs in 10 games with the Peoria Javelinas.

Others considered: Victor Robles, OF, Nationals; Francisco Mejia, C/3B, Indians; Kyle Tucker, OF, Astros; Ronald Acuna, OF, Braves.

Luis Urias on getting better

Best power
Ronald Acuna, OF, Braves

Acuna totaled just eight homers in his first two pro seasons before busting out with 21 this year as he advanced from high Class A to Triple-A at age 19. His exceptional batting speed translates into power to all fields, and he should be good for 30 or more homers per season in his prime. Acuna has gone deep four times in 15 games with Peoria, leaving him one off the AFL lead, while pacing the league in hitting (.377), on-base percentage (.698), runs (18), hits (20), extra-base hits (nine) and total bases (37).

Others considered: Michael Chavis, 3B, Red Sox; Chris Shaw, OF/1B, Giants; Kyle Tucker, OF, Astros; Austin Riley, 3B, Braves.

Acuna on win, Fall success

Fastest runner
Victor Robles, OF, Nationals

This is pretty much a tossup between Robles and Acuna, who both possess well above-average speed. Acuna has demonstrated more basestealing acumen to this point, while Robles may be a shade better defender in center field. Robles, who joined the Mesa Solar Sox late because he was participating in the National League Division Series, has similar all-around tools to Acuna, with more pure hitting ability but less power.

Others considered: Ronald Acuna, OF, Braves; Braden Bishop, OF, Mariners; Corey Ray, OF, Brewers.

Strongest arm
Francisco Mejia, C/3B, Indians

Mejia has drawn the most attention for his modern Minor League record 50-game hitting streak in 2016, but it's actually his arm that grades out as his best tool. Some evaluators give it an 80 on the 20-80 scouting scale, and he has thrown out 34 percent of Minor League basestealers. Mejia is playing third base for the Glendale Desert Dogs as the Indians look for a way to incorporate his bat into their lineup.

Others considered: Victor Robles, OF, Nationals; Ronald Acuna, OF, Braves; Sheldon Neuse, 3B/SS, Athletics.

Mejia going to Fall Stars Game

Best defender
Luis Guillorme, SS/2B, Mets

Guillorme stands out with his hands, quickness and instincts, which along with his solid arm allow him to make all the plays at any infield position. He's a tick better defender than Mets incumbent Amed Rosario at shortstop, though his offensive ceiling isn't as high and he may wind up a utility man. Guillorme has played both middle-infield positions for the Scottsdale Scorpions.

Others considered: Victor Robles, OF, Nationals; Ronald Acuna, OF, Braves; Braden Bishop, OF, Mariners; Tomas Nido, C, Mets.

Best fastball
Mitch Keller, RHP, Pirates

Other Fall Stars such as Orioles left-hander Tanner Scott may light up radar guns a little more, but Keller has the best fastball package in the game. He not only works at 92-96 mph and tops out at 98, but his heater also comes with late life and he usually commands it well down in the strike zone. Keller has been sharp in four starts for Glendale, positing a 1.72 ERA, .151 opponent average and 10 strikeouts in 15 2/3 innings.

Others considered: Tanner Scott, LHP, Orioles; Sandy Alcantara, RHP, Cardinals; Gerson Moreno, RHP, Tigers; Touki Toussaint, RHP, Braves.

Keller's solid start

Best curveball
Touki Toussaint, RHP, Braves

While Toussaint can pump mid-90s fastballs, his curveball nevertheless is his most devastating pitch when at its best. It can be an absolute hammer with power and depth that confounds lefties and righties alike. Toussaint is still figuring out how to harness his stuff, however, which is why he has 10 strikeouts in 6 1/3 innings with Peoria but also a 9.95 ERA and 10 baserunners allowed (including three homers).

Others considered: Mitch Keller, RHP, Pirates; Adbert Alzolay, RHP, Cubs; Jordan Hicks, RHP, Cardinals.

Best slider
Justus Sheffield, LHP, Yankees

There were times earlier in his pro career when Sheffield's curveball looked like it would be his best secondary pitch, but his mid-80s slider has surpassed it. He also has a 92-96 mph fastball and one of the AFL's better changeups, and the package makes him one of the best southpaw pitching prospects in the game. Sheffield ranks second in the league with 21 strikeouts and owns a 2.37 ERA in 19 innings for Scottsdale.

Others considered: Yency Almonte, RHP, Rockies; Matt Festa, RHP, Mariners.

Sheffield on Fall League

Best changeup
Sandy Alcantara, RHP, Cardinals

Though he's known as a power pitcher with an upper-90s fastball and a mid-80s slider, Alcantara possesses a pretty nifty changeup as well. He maintains his normal arm speed when he throws it and it was his most effective offering during his September callup with the Cardinals, sitting in the low 90s with tumble. Alcantara battles his control and command at times and has done so with the Surprise Saguaros, recording a 5.73 ERA in four starts.

Others considered: Justus Sheffield, LHP, Yankees; Kirby Bellow, LHP, Diamondbacks.

Best control
Mitch Keller, RHP, Pirates

Keller throws strikes with his entire arsenal, which includes a curveball that looks like a future plus pitch and an effective changeup. In two years of full-season ball, he has posted a 247/50 K/BB ratio in 240 1/3 innings. Keller has issued just four walks in his 15 2/3 AFL innings.

Others considered: Adbert Alzolay, RHP, Cubs; T.J. Zeuch, RHP, Blue Jays; J.D. Hammer, RHP, Phillies.

Jim Callis is a reporter for MLB.com. Follow @jimcallisMLB on Twitter. Listen to him on the weekly Pipeline Podcast. This story was not subject to the approval of Major League Baseball or its clubs.