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.

Hit Tool

Top Hitter in the Minor Leagues: Oscar Taveras (St. Louis Cardinals)
After earning top honors in this series last year, Taveras’ injury-shortened 2013 season did nothing to alter opinions regarding his potential hitting ability. Blessed with some of the best hands in the game and an innate feel for getting the barrel to the baseball, Taveras projects as an elite hitter who could win multiple batting titles in his career. Unlike many players with violent swings or aggressive approaches in the box, Taveras makes it all work thanks to the combination of tremendous bat speed, exceptional hand-eye coordination, and an unexplainable gift for hitting. Saying Taveras is the best hitter in the minor leagues may actually be selling him a bit short, as he could be one of the best hitters in baseball the second he steps on the field in St. Louis.

Other Players Considered: Nick Castellanos (Detroit Tigers), Rougned Odor (Texas Rangers), Raimel Tapia (Colorado Rockies)
As good as each of these players could be, none of them can match the hitting potential of Taveras. Castellanos has drawn praise as a gifted hitter since the day he signed with the Tigers, and after a rough start to the 2013 season, he adjusted to the competition and showed off his superb hitting skills before a promotion to Detroit late in the year. While he may not compete for batting titles over the long haul, scouts consistently project him to hit .290-.300 at the major-league level. One of 2013’s breakout prospects, and the top prospect in the Rangers system, Odor is a natural hitter who makes easy contact on all types of pitches. He handles the bat extremely well and has enough punch in his swing to keep pitchers honest. Odor’s potential as a hitter rests in the plus-plus range, and there are scouts who believe he can be a consistent .300 hitter in the big leagues. Despite just turning 20 this winter, Tapia draws unanimous praise from scouts for his hitting ability and potential to evolve into one of the game’s top hitting prospects. Still young and in need of refinement, Tapia’s raw gifts in the batter’s box are obvious, and the 2014 season could represent his coming out party.

Top Major League Hitter: Miguel Cabrera (Detroit Tigers)

All-Time Tool: Tony Gwynn

How to Identify It: “Can a guy hit .300?” is a tough question and, honestly, it’s not that good a question. “Does the hitter do the things that will allow him to hit .300?” is a better question. Great hitters do certain things that allow them to hit for a high average.

Great hitters start their processes (gather, load, etc.) early. Whether it’s through a big leg kick, a double tap of the front foot, or raising the front heel, they make sure to give themselves enough time to read and react to the pitch. Starting early makes tracking the ball easier. It's hard to track a 95 mph fastball. It’s even harder when you're trying to rush the swing and likely moving the head around.

Short of taking a player into an optometrist’s office, it can be difficult to accurately judge his vision. Vision is criminally underrated in the evaluation of hitting. Scouts need to look at how the hitter reacts to pitches close to the zone as opposed to far from the plate. Is a hitter shutting the swing down early only to see the ball catch the heart of the plate? Not a good sign. Scouts need to be able to glean information about a hitter just by observing the pitches he takes.

When the moment of truth arrives and the hitter makes contact, listen for the sound off the bat. There is a different sound when the sweet spot of the bat hits the ball, and good hitters make this sound on many of their swings. Look at how the ball comes off the bat. Is it slicing or tailing? This is a sign that the bat isn’t square to the ball. Look at the batter. Is he falling off to one side or does he have a good sense of balance?

Now, one good swing does not an all-star make. Great hitters will repeat their swings. Don’t think this means that all swings need to be simplified. Some hitters need the bat wiggle, the big leg kick, or the crazy stance in order to be cognizant of how their body is moving.

It’s foolish to project hitters based solely on who has the most textbook swing, but players do need solid swings to turn around big league heat, just like they need strength and enough bat speed. Evaluating and projecting the hit tool is one of the most-respected skills any scout can possess. Ryan Parker and Chris Mellen

Power Tool

Top Power in the Minor Leagues: Javier Baez (Chicago Cubs)
Among the prospects in the game with elite raw power, Baez takes the cake because of his ability to translate that power to game situations. Despite being an ultra-aggressive hitter, Baez’s ability to consistently make contact allows him to tap into his raw power and could lead to him dropping 35-40 bombs a year in the majors. Elite raw power is rare, but the ability to bring that type of raw from batting practice into games is even rarer. Of the players considered for this list, Baez is clearly the best bet to actualize his top-of-the-scale raw power, and he could begin doing that as soon as this summer.

Other Players Considered: Kris Bryant (Chicago Cubs), Joey Gallo (Texas Rangers), Steven Moya (Detroit Tigers), Miguel Sano (Minnesota Twins), Oscar Taveras (St. Louis Cardinals)
Each player considered behind Baez offers at least plus-plus raw power, with players like Gallo, Moya, and Sano bringing elite raw to the table. While all three players can put on jaw-dropping displays in batting practice, and both Gallo and Sano have shown some ability to bring that power into games, the trio lacks projection in the hit tool. It's easy to dream on the raw power and imagine 35 home runs a year, but all three players will likely come up short of that projection. Bryant’s raw power rests a half grade behind the others, but he should bring a significant portion of his raw pop into games, allowing him to hit 30-plus home runs a season. Taveras is the only player considered for this list who lacks true or near elite raw power, but his unbelievable feel for hitting allows every ounce of his plus-plus raw power to show up in games.

Top Major League Power: Giancarlo Stanton (Miami Marlins)

All-Time Tool: Mickey Mantle

How to Identify It: Identifying power can be a tricky task, since hitters need enough utility in the hit tool to let any sort of power show. Power comes from a blend of bat speed, strength, and mechanics. Bat speed is the easiest of these to spot. Not only will the bat be moving faster through the zone, but the hitters with bat speed get precious extra time to read and react to the ball. Strength is a bit less obvious, and size can play into identifying it. A hitter who is 6-foot-2, 220 pounds is likely to possess at least some strength and may be easier to project for power. Scouts also listen for the sound of the ball off the bat. Power hitters hit the ball with a sound more akin to a cannon going off rather than the usual “thwack.” Strong hitters can drive the ball even if they miss the barrel of the bat.

Power hitters have some features in their swing mechanics that can help project future power. Ideally, these mechanics should be smooth and fluid. Usually power hitters will clear their hips early without opening their upper half. When the upper body does fire, they launch the bat through the zone on a flat plane, finishing above the shoulders. At the tail end of the swing, look to see if they are getting any sort of extension with their arms. Power comes from the legs, so young hitters need to show some sort of lower half involvement. The back knee should drive forward and down toward the plate and actually pull the back foot along for the ride; Bryce Harper is the most extreme example of this movement.

There is a saying that power is the last tool to develop in hitters. But scouts are tasked with observing young hitters, which makes looking for a blend of physical gifts and mechanical tendencies that portend power one of the most difficult aspects of the job. —Ryan Parker

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