It's "best tools" week! For the third straight year, Keith Law lays out his rankings (and reasoning) for the players with the best tools in baseball. To complete this year's rankings, he evaluates the best fielders and the best arms behind the plate, in the infield and in the outfield (see last year's rankings here). See this year's hitting tools rankings here, and pitching tools rankings here.

Catcher glove

1. Austin Hedges, San Diego Padres

2. Yadier Molina, St. Louis Cardinals

3. Tyler Flowers, Atlanta Braves

4. Martin Maldonado, Los Angeles Angels

5. Buster Posey, San Francisco Giants

Hedges has always had the reputation as an elite receiver, both with his glove and his arm, and now he has had the regular playing time to prove it. He's third in Baseball Prospectus's pitcher-framing metric and in its overall fielding runs metric for catchers, but he's a better receiver and blocker than the two guys ahead of him in that metric -- Flowers, who has become an elite framer, and Yasmani Grandal, who frames well but catches poorly. I do consider framing in this category, because teams do too, but it's worth noting that performance in that category might be ephemeral -- Jonathan Lucroy, among the best framers in the game the last few years, rather suddenly became the worst in 2017.

Catcher arm

1. Willson Contreras, Chicago Cubs

2. Jorge Alfaro, Philadelphia Phillies

3. Yadier Molina, St. Louis Cardinals

4. Gary Sanchez, New York Yankees

5. J.T. Realmuto, Miami Marlins

Contreras' caught-stealing numbers might not reflect it, in part because Cubs pitchers don't do a lot of that whole "holding runners on" thing, but he has a cannon and it's very accurate. So while Alfaro or Sanchez might have the edge in pure arm strength, I give Contreras the nod for best arm overall. Of course, Molina's arm strength and accuracy are so good that teams run on him less frequently -- although I wonder if there's a lag between any physical decline in his skills and when teams will try to test him. Alfaro has one of the strongest catcher arms I've ever seen and loves to show it off, but his receiving is still iffy enough that I think there's some chance he ends up at another position. Austin Hedges just missed the cut.

Infield glove

1. Andrelton Simmons, SS, Los Angeles Angels

2. Manny Machado, 3B, Baltimore Orioles

3. Nolan Arenado, 3B, Colorado Rockies

4. Jose Iglesias, SS, Detroit Tigers

5. Anthony Rendon, 3B, Washington Nationals

Simmons is having an MVP-caliber year across the board, generating 4.5 WAR (via FanGraphs' blend) already, boosted by a career year at the plate and his usual Hall of Fame-level defense. Simmons already ranks 40th all time in defensive WAR on Baseball-Reference.com despite only six seasons and 741 games; no one else in the top 150 has under 800 games career. Arenado is actually 155th on that list and the next-highest ranked player under that games played mark; he and Machado are separated by about half a win. I'd entertain either of those guys as the best third baseman in baseball but give a slight edge to Machado because he's rangier and could easily play shortstop, though that's no slight to Arenado.

Infield arm

1. Andrelton Simmons, SS, Los Angeles Angels

2. Manny Machado, 3B, Baltimore Orioles

3. Nolan Arenado, 3B, Colorado Rockies

4. Carlos Correa, SS, Houston Astros

5. Anthony Rendon, 3B, Washington Nationals

Simmons is going to own this category for a very long time, unless Hunter Greene, the Reds' first pick in this June's draft, reaches the majors as a shortstop instead of on the mound. Machado was probably the hardest-throwing amateur infielder I'd seen before Greene -- I never saw Simmons in junior college. All of these guys have cannons, which is why they're all found on the left side of the infield; among players on the right side, just-recalled Mets first baseman Dominic Smith might have the best arm, as he pitched some in high school, and I saw him hit 91 mph while starting a game against Conner Greene, now in the Blue Jays' system.

Outfield glove

1. Billy Hamilton, Cincinnati Reds

2. Mookie Betts, Boston Red Sox

3. Byron Buxton, Minnesota Twins

4. Kevin Kiermaier, Tampa Bay Rays

5. Ender Inciarte, Atlanta Braves

I don't think there are any surprises here either. Kiermaier was a somewhat tough call since he's just coming back from both a hairline fracture in his hip and a back issue that has bothered him while he has been rehabbing, so there's at least some small chance he loses a little range in the aftermath. Buxton has the potential to pull a Simmons and take over the top of this list for the next decade, depending on his improving his reads in the field and, of course, continuing to hit well enough to ensure that he plays every day.

Outfield arm

1. Bryce Harper, Washington Nationals

2. Aaron Hicks, New York Yankees

3. Byron Buxton, Minnesota Twins

4. Adam Jones, Baltimore Orioles

5. Brad Zimmer, Cleveland Indians

The first four guys on this list all pitched as amateurs, enough that they were at least considered in their draft years as possible pitchers before they were drafted as position players. Zimmer is the exception, but his brother, Kyle, was drafted fifth overall as a pitcher and is still in the Royals' system in Triple-A. Hicks holds the current StatCast record for the hardest recorded throw from the outfield at 105.5 mph. All are guys I'd like to see on the mound at some point later in their careers when their teams need some mop-up work, although you couldn't risk any of their arms right now given what they do at the plate.