The National League West is home to a handful of baseball's best all-around players. Unsurprisingly, those players boast some of baseball's most impressive game-changing tools.
There aren't many big leaguers who change the way their opponents prepare because of a singular skill -- whether it's light-tower power, lights-out defense or a rocket arm. But every NL West club has a few.
This week, MLB.com broke down the singular most elite tool on every team in the division. The list is littered with some of the game's most exciting ballplayers, and it's easy to see why.

D-BACKS
The player and his tool:Zack Greinke's command
Why it matters: There was once a time when Greinke regularly pumped fastballs in the mid-90s, using the pitch as a weapon to get hitters out, even when he missed his location. That time has passed by about half a decade. And yet Greinke remains one of the top pitchers in the NL.
That's almost exclusively because of Greinke's pinpoint command and craftiness. His fastball sits around 90 mph this season, and yet he owns a 3.00 ERA and is striking out more than a hitter per inning.
Greinke consistently mixes about half a dozen pitches into his starts. He locates each with precision and offers little in the way of predictability.
Signature moment this season: Greinke pitched eight innings of two-hit ball against the Rockies on July 22. He struck out 13 and recorded 17 swinging strikes -- two with his fastball, four with his changeup, one with his curveball, seven with his slider, one with his sinker and two with his eephus.

DODGERS
The player and his tool:Yasiel Puig's arm
Why it matters: There aren't many tools in baseball that have drawn as much fanfare as Puig's arm. From the moment he arrived in 2012, he put it on full display, turning a game-ending double play in his debut against the Padres from the right-field warning track.
Sure, Puig has drawn some criticism for being careless with his throws, but there's no question he can change a game from out of nowhere with his other-worldly arm strength.
Puig's lasers land on all sorts of highlight reels. But his impact stretches beyond that. Puig has kept countless baserunners in check with the mere threat of his arm. There aren't many outfielders who inspire legitimate fear on the basepaths, but he is one.
Signature moment this season: With the Dodgers and D-backs tied in the 14th inning on April 2, A.J. Pollock lifted a deep drive to the right-field warning track. Against most outfielders, Ketel Marte would've reached second base standing up. But Puig made the catch, spun, and threw a strike to second base on the fly. Marte was toast.

GIANTS
The player and his tool:Buster Posey's hitting
Why it matters: Throughout his career, Posey has always been an outstanding defensive catcher. But there are plenty of outstanding defensive catchers. None can hit like Posey.
Since his rookie campaign in 2010, Posey has never batted below .284. He's flirting with .300 once again this year. Posey has posted an OPS+ of at least 110 in nine straight seasons since '10. Only Joey Votto, Giancarlo Stanton and Robinson Cano have done the same (with a minimum of 100 at-bats). No other catcher is even close. Yasmani Grandal and Yadier Molina have had five such seasons.
Sure, defense is generally regarded as a catcher's most important attribute, and Posey brings plenty of that. But he can win games with his bat just as easily.
Signature moment this season: In a tie game in the 13th inning, Posey delivered a walk-off single against the Cubs on July 11. He went the other way with a 97-mph fastball and served it off the right-field wall for the game-winner.

PADRES
The player and his tool:Austin Hedges' defense
Why it matters: The Padres have fully committed to their youth movement. Nowhere is that more evident than in their starting rotation. Already this season, Joey Lucchesi, Eric Lauer, Brett Kennedy, Jacob Nix and Walker Lockett have debuted as starters.
In the Padres' eyes, it's essential that their young arms have a reliable presence behind the plate. Hedges is as steady as they come. Over the past few weeks, he has begun to turn a corner with his bat. But Hedges' defense remains his calling card.
Hedges' best attribute is his pitch-framing ability, and for the second straight season, he ranks near the top in most framing metrics (though not quite so high, because he missed a month and a half with elbow tendinitis). He can also impact play with his blocking ability, his arm, his game-calling and his overall athleticism.
Signature moment this season: In an April game against the Giants, Gregor Blanco attempted to lay down a bunt and popped it up behind the plate. Hedges made an all-out diving grab, then threw to first base from his backside to double up Brandon Crawford. Good luck finding a better play from a catcher this season.

ROCKIES
The player and his tool:Nolan Arenado's power
Why it matters: There might not be a toolsier player in the NL West than Arenado. He's got a cannon. He routinely hits above .300. Arenado is one of the best defenders in the world.
But this season, Arenado's most impactful attribute has been his power. It is, quite literally, a game-changer. He's given the Rockies a lead 11 times this season with a home run.
No one pulls the ball with authority quite like Arenado. His pull-side slugging percentage has hovered around 1.000 this year, and it's a big reason why he's challenging for the league lead in homers and RBIs.
Signature moment this season: Locked in a tight NL West race, Arenado made his presence felt against Arizona on July 20. He took Robbie Ray deep in the top of the first inning. Arenado went deep again in the fifth, clubbing a game-tying two-run shot. Colorado won the game, an 11-10 slugfest.