Describing the 5 tools of baseball, through the stats and the eyes of scouts

What exactly do we mean when we talk about players’ tools? I think most fans by now know what the five tools are for position players — hit, power, run, glove, arm — and know that a “five-tool” player has above-average or plus grades in all of them. (And, hopefully, most fans know that there are more players called “five-tool” players than there are actual five-tool players.)

These tools have long-standing definitions, or at least general meanings, in the scouting world. But the advanced data made available to teams over the past five seasons via MLB’s Statcast system and similar technologies at other levels of baseball have now allowed R&D departments to put objective measures up against those same tools. In this piece, we will look at each of the five position-player tools and try to define them from scouting and analytical perspectives, while providing examples of players with grade-80 tools and, where possible, grade-20 tools, or just players at the bottom of the major-league scale. We’ll do the same for pitcher grades in a future column.

Hit

Keith Law: Of all five tools for hitters, none is as hard to project as the hit tool. Looking at a 17-year-old high school player or a 15-year-old prospect in the Dominican Republic and trying to determine how well he’ll hit pro pitching — or major-league pitching — seems like a fool’s errand. If you get within a half-grade, that’s a win.

Part of the problem is a semantic one: Does the hit tool refer to the ability to put the bat on the ball, or the ability to hit it hard? Where does the hit tool end and the power tool begin? Do you have to hit .300 for a plus hit tool, or are we satisfied with high contact rates even if they don’t result in enough of a batting average?

I was never taught a specific definition of the hit tool, but I’ve come to use it to refer to the ability to make quality contact. Not just any contact, mind you, but quality contact. If contact were the only goal, Nick Madrigal, who posted the lowest strikeout rate in organized baseball last year, would have an 80 hit tool, or at least the highest hit tool of any prospect. Contact is not the goal, however; hard contact, the kind that results in base hits and extra bases and the power to advance runners, is. All contact is not created equal, and some contact might even be undesirable (he writes, as, in a parallel COVID-19-free universe, Albert Pujols rolls over into another 6-4-3 double play).

But I’m going to hedge a bit on that definition, too: You have to make enough contact for this to work. Yoán Moncada has the highest BABIP of any MLB hitter over the past three seasons, signifying at least a high rate of hard contact (and, likely, some good luck), but he has also struck out over 30 percent of the time. He’s making high-quality contact when he’s not striking out. Domingo Santana has done just about the same thing, and I don’t think anybody is confusing his hit tool with an 80.

So the best answer I can give on the hit tool is that it’s an interaction between the two. If you remember linear programming from high school or college math, it’s a bit like that: Somewhere there’s a point where the two constraint lines intersect, and that’s the optimal answer. You want all the hard contact and not much of the soft kind; you don’t want excessive swing and miss, but nearly every hitter in the past 20 years who’s made a lot of hard contact has struck out at least 15 percent of the time. Mike Trout is the exemplar here: he strikes out about 20 percent of the time, over 100 times a year, but he consistently makes high-quality contact. He has an 80 hit tool — and I don’t think that’s a controversial opinion.

There aren’t many other hitters in the majors who might earn that tag; I’d probably put one on Alex Bregman, and we could talk about Anthony Rendon, but the list is short. I don’t think I’ve ever projected any prospect, including those three, to have an 80 hit tool for the same reason. It’s a rare skill, and we don’t know if a guy has it until he’s faced major-league pitching.

As for the bottom end of the scale, outside of pitchers we almost never see 20 hit tools in the majors; if you’re that bad with the stick, you’re probably not going to hit enough in Triple A to get a call-up. Chris Davis is probably the worst hitter in baseball right now, and I’d give him a 30 hit tool; Billy Hamilton would be the same. Terrance Gore is the only major-leaguer in recent memory I’d give a 20 to — and his employers seem to agree, as he racked up just 77 plate appearances in 100 games, playing more for his legs than anything else.

Eno Sarris: Yeah, if it’s tough to describe hit tool from the scouting standpoint, it’s even tougher in the statistical sense. At first, it seems to make sense to combine some aspect of contact rate and power to get at that “powerful contact” aspect of hit tool, but then a team analyst pointed out to me that missing the ball completely might be a better outcome than mis-hitting the ball and putting a dribbling grounder in play. All contact is not ideal contact.

You might start with line-drive rate, and say that players such as Freddie Freeman, Omar Narváez and Whit Merrifield are the hit tool champions of the past five years. And that has some sense to it, a good hit tool has to produce line drives repeatedly. But the problem is in the definition of the line drive — they’ve traditionally been defined by humans at games, who through no fault of their own might show bias. In other words, if the ball gets outfield grass, it’s more likely to be called a line drive even if a caught ball on the infield was smoked way harder.

So then you can use Statcast to define a line drive and be more precise about it. Since production on non-homers peaks at 12-13 degrees, a range from 6-19 degrees captures the “line drives” best. After you cut all balls that left the bat slower than 90 mph, you’ve got a better line-drive rate. Thirteen percent of balls in play were in those angles and exit velocities, and they collectively produced a .717 average in the Statcast era.

Here are your line-drive percentage leaders in the Statcast era:

Looks pretty good to me, even if there are a few surprises on the list. Maybe you could argue that this list, which is line drives over balls in play, is inferior to this other list, which is line drives over plate appearance. But then we’re arguing about how much we value power versus contact in the hit tool again.

We’re also taking just a sliver of their entire batted-ball outcomes and evaluating them from that. Is there a way to look at a player’s entire batted-ball profile and produce some sense of their hit tool?

Alex Chamberlain at FanGraphs did something fun recently, as did Brock Hammitt of the Brewers’ player development group, when they looked at “launch-angle tightness.” In other words, which players were good at focusing their balls in play? Which players avoided the bad grounders and bad pop-ups and produced things that looked like line drives, even if they weren’t line drives according to whatever arbitrary definition we’ve come up with?

These players have the tightest launch angles (aka smallest launch angle standard deviation) from Chamberlain’s effort:

We’ve got many of the same players, but if you compare this list to the line drives over plate appearance list linked above, you’ll see that many of the lighter-hitting players have disappeared. This list is full of players with the ability to make powerful contact and avoid the mis-hits that produce pop-ups and weak dribblers. Perhaps these are your 80-hit tool major leaguers?

80 hit tool: Freddie Freeman
30 hit tool: Rougned Odor

Power

Law: What is power, exactly? When a scout refers to power, does he mean just pure physical strength, or a player’s potential to hit home runs?

That might seem like a distinction without a difference, but there is such a thing as a player with power that doesn’t play in games. They’re called 5 o’clock hitters, a reference to the time when they might be taking batting practice. Ryan Sweeney was probably the best example I ever saw of a hitter who’d show you plus power — maybe more than just plus, in his case — in BP but couldn’t seem to clear the fences during games. He hit just 23 homers in over 2,100 major-league at-bats and was out of pro ball before he turned 30.

That’s why we distinguish between “raw power” and “game power” when talking about players from a scouting perspective. Raw power is somewhat easy to discern because it’s there in BP, and when you watch BP you never run into the problem of hitters not swinging or not getting anything to hit. I saw Devin Mesoraco in high school, in Punxsutawney, Pa. (I didn’t bother any groundhogs, though), where he came to the plate four times and saw 16 pitches, none of them in the strike zone, 12 of them intentional balls. Tough to tell you if he had game power off that look, but he showed raw power in BP.

Game power is a different animal, and it is a bit dependent on a player’s hit tool as well — you can’t hit for power if you can’t hit, as the old scouting axiom goes — although I try, when possible, to tease the two apart. Does the player have the swing path, the hand speed and the strength required to hit for power against actual MLB-caliber pitching? Perhaps he won’t make enough contact to reach his game-power ceiling, but I try to predict what power he’ll show if he hits at all.

The best raw or game power I’ve ever seen myself in a prospect belonged to a high school hitter from Las Vegas named Joey Gallo, who swung and missed a lot, even at that level, but who could hit balls farther and louder than anyone I’d seen before or since; I was even at the game where he tied the Nevada state career home run record, with just two scouts alongside me that day. (I’ll never understand why there weren’t more scouts there since his team was facing elimination.) There are quite a few major leaguers with 80 power right now, and a couple of prospects who have it or project to get to it (Nolan Gorman of the Cardinals is one), but Gallo’s 80 is a different number than everyone else’s.

I don’t think you can be a major-leaguer with 20 power; the bottom of the realistic scale, once you’ve limited the pool to players who can hit MLB pitching at all, is either 30 or 35. That’s Billy Hamilton or Dee Gordon or, going back a few years, Ben Revere — guys who might have posted isolated power figures under .050 if their speed didn’t buy them a bunch of triples. If you don’t have grade-35 power, I don’t believe you can hit major-league velocity enough to be anything at the plate; you’d better play some elite defense at a position up the middle if you want to play at all.

Sarris: Finding the right statistic for power seems like it should be incredibly easy. Sort that leaderboard for dingers, done.

But … we can do better. For one, that’s a counting statistic, so even though someone such as Yordan Álvarez probably has top-of-the-scale power, he only shows up at the top of your leaderboard if you shrink the timeframe considerably. Using home runs as the marker also ignores other powerful outcomes such as doubles and triples. Plus, why use a hammer when you have a scalpel?

Statcast has given us better power measurements such as exit velocity, the measure of how hard the ball comes off the bat. But sort the average exit velocity leaderboard and a few strange names jump to the top — do you think of DJ LeMahieu as having 80-grade power? Ryan McMahon? Nick Markakis was 30th in overall average exit velocity last year! They hit the ball hard, but not in the air, which is an important part of power.

Enter Barrels, a statistic that measures how often a hitter hits the ball hard and in the angles that produce the most power. Here’s a picture from Statcast’s glossary to better understand the barrel zone.

(MLB.com / Statcast)

What you get by defining power this way — instead of using your standard historical stats — is a metric that more quickly captures what it attempts to measure, and also is steadier year to year. That is to say that Barrels “stabilizes” quicker (the stat becomes meaningful quicker than other power metrics) and is “sticky” year to year (the stat is better correlated year to year than other power metrics).

Though the specifics of the stat are a little complicated, the concept is not, and the leaderboard is practically flawless. Miguel Sanó, Aaron Judge … and yes, there’s Álvarez, sixth in the league in barrels per batted ball.

80 power: Aaron Judge
30 power: Billy Hamilton

Speed

Law: Scouts have measured speed via home-to-first running times for longer than I’ve been in the business, which is good in that there’s a consistent and mostly objective method of doing so, but not so good in that not every player gets the same sort of jump out of the box. (The scale does vary for left- or right-handed batters, so that one particular bias is not an issue.) Jacoby Ellsbury comes to mind as a player who was a 55 runner out of the box, but a 70 runner underway; his first step was just not very good. Some hitters also get a “jailbreak” first step because their swings already set them on the path down the line to first base — Ichiro’s entire approach at the plate was built around slapping the ball to the left side and getting out of the box as quickly as possible, while the Reds tried to make Billy Hamilton a switch-hitter so he could take advantage of his own otherworldly speed in the same way.

There are always a bunch of 80 runners around the minors because that’s a tool that can’t be taught and is very rarely improved after a player hits age 22 or so, and teams will draft or sign such prospects hoping they’ll eventually learn to hit. There’s also the belief, not without some foundation, that you can take an 80 runner and make him a center fielder, although Joey Gathright comes to mind as an 80 runner who couldn’t play center field if you gave him a map and a compass. Hamilton is the fastest player I’ve ever personally clocked, although he’s never hit enough to make it as a regular; among players with other baseball skills, I’d tab Byron Buxton as the fastest. Among prospects, San Diego shortstop CJ Abrams is the only 80 runner on my top 100 this winter, although there are a few other 80 runners kicking around the minors.

Speed is also one of the only tools where you’ll see a legitimate 20 grade on a major-leaguer; Albert Pujols has been a 20 runner for several years now, for example. You can play a corner or even be a DH with 20 speed, whereas you aren’t a major leaguer if you have a 20 hit tool or 20 power and can only DH when you have a 20 arm.

Sarris: The story of speed statistics is pretty funny if you think about it.

As long as there have been scouts, they’ve recorded times to first as the best measure of a player’s speed.

But those numbers weren’t available to the general public, so the public analysts tried various outcome-based statistics. After the modern rule for stolen bases was adopted in 1898, and tweaked again in the 1930s and 1950s, there was a large gap in innovation before Bill James introduced Speed Score in 1987. That statistic incorporated stolen base percentage, stolen base attempts, triples, runs scored, grounded into double plays and defensive range in order to better capture the various ways a player could benefit from speed. Later, the makers of Wins Above Replacement added a baserunning stat called BsR to their overall metric to do some of the same.

When Statcast introduced Sprint Speed, it felt like we finally were getting access to the numbers scouts have been using forever. It felt like we were done trying to approximate the thing using the on-the-field results, and were finally directly measuring the tool that we were trying to measure. Tim Locastro is the fastest man in baseball, then.

Well, it turns out that Sprint Speed is less predictive of all those speed-based on-field results than … times to first. It turns out that, when it comes to the numbers, there’s something of a “game speed” vs. “straight-ahead speed” — just as Keith pointed out. And times to first better capture all of the skills needed to turn speed into successful baseball outcomes better than top sprint speeds do.

So we’ve come full circle, and the old school was right. Now Miami’s Magneuris Sierra is the fastest man in baseball, and players such as Kevin Kiermaier and Cody Bellinger have better game speed than 99 percent of the league despite being outside the top 20 in straight-ahead speed.

The more things change, the more they stay the same.

80 speed: Byron Buxton
30 speed: Vladimir Guerrero Jr.

Glove

Law: Although the hit tool is the hardest to predict when evaluating prospects — especially teenaged ones — the glove tool is the most ambiguously defined of the five. Is it a measure of overall fielding, sans arm? Or is it more specific, such as describing a player’s range or his hands or his instincts? Simply calling it “glove” is misleading in and of itself, because it implies that it’s about the player’s hands. And maybe that’s why the idea of thinking about fielders in terms of errors or fielding percentage — which is about as useless a measure of fielding prowess as you could find — still persists in some corners of fandom and even the baseball media. I can’t speak to anyone else’s definition but mine; I think this tool, whatever we call, should include all aspects of fielding other than the player’s throwing arm.

We seem to live in a golden age of 80 fielders, too. Andrelton Simmons might be the best defensive shortstop in history, and he’s at least the best since Ozzie Smith (yes, better than Omar Vizquel). Matt Chapman is an 80 defender at third, and Byron Buxton is one in center field when he’s healthy. In the minors, Atlanta center fielder Cristian Pache is the best defensive prospect at any position, and Pittsburgh third baseman Ke’Bryan Hayes isn’t far behind. Both are at least 70s and project to 80 if they’re not already there.

I don’t think there are any 20-grade defenders in the majors currently playing those positions — although there are players who were 20 defenders at positions they played previously but have since moved to easier positions or just to DH. Toronto third baseman Vlad Guerrero Jr. is probably the worst defender in the majors right now at the position he’s currently playing — and he doesn’t project to get better — but I’d probably call him a 30 defender there rather than a 20, so, yes, it could be worse. One player to watch in this category is Milwaukee second baseman Keston Hiura, who played about half a season in 2019 and was in the bottom 5 percent of all fielders at all positions in UZR/150 – consistent with scouting reports that questioned his defense and his weak arm going back to his draft year in 2017.

Sarris: As Keith points out, we’ve long had defensive statistics and they’ve long been poor ways to evaluate defense. Consider the oldest one, fielding percentage. It asks how many outs you make by way of putouts or assists, divided by how many chances you’ve had. But there’s a glaring problem with this method — it doesn’t account for range at all. A lesser defender could stand still and get every ball hit right to him and look like a defensive star.

J.J. Hardy has a better fielding percentage than Ozzie Smith. J.J. Hardy probably wasn’t a better defender than Ozzie Smith.

So range was a key factor when public analysts tried their hand at improving defensive statistics. Ultimate Zone Rating, Defensive Runs Saved and Fielding Runs Above Average all try to get at the ability of a defender to both get to a lot of balls and turn them into outs.

With Statcast, we have the chance to improve upon those metrics, at least theoretically. Once again, instead of looking at outcomes, we now have the chance to look at the process of fielding a ball. With Statcast, we have the player’s starting position, so we can figure out how many steps they took to get to the ball, a key factor in determining range.

Statcast took that information and created Outs Above Average, so we could maybe say with some certainty that Víctor Robles is one of the best defenders in the league. But how certain can we be? When I looked at OAA and how sticky it was year to year, it didn’t perform all that well, and then there was some debate that perhaps players’ true-talent defensive abilities change a lot year to year. One thing is true no matter how you evaluate defense — you’re doing so with less of a sample than with offensive statistics. A player gets 600-700 plate appearances in a full year at the plate. Paul DeJong got a league-leading 359 balls in his zone last year, of which around 90 percent were “at-em” balls. That probably doesn’t tell us much about his defensive skill.

In an interesting twist, Baseball Prospectus recently evaluated the current state of defensive metrics and found that their FRAA was best in the outfield, and OAA was best on the infield. So maybe we should use a different player to illustrate 80 defense. (And yeah, there isn’t really a great stat that uses our best inputs and separates arm from the equation.)

80 defense: Javy Báez
30 defense: Keston Hiura

Arm

Law: This one is pretty easy from a scouting perspective — even though there’s still a strong subjective component — because there’s usually broad agreement on these grades. You know a plus arm when you see it; you know an 80 arm because you want to refer to it as some kind of weapon: a laser, a cannon, a howitzer. Andrelton Simmons, who would sit 98 mph as a pitcher in junior college, has one, and so does Brett Phillips. Byron Buxton is here yet again; he touched 99 as a pitcher and I saw him sit 90-94 while starting in high school. Matt Chapman has an 80 arm as well, and of course, Mike Lorenzen has such a strong arm he’s also a pitcher. You just have to throw very hard to get a 70 or 80 grade here; accuracy isn’t part of the grade.

A 20 arm is usually the result of an injury — I think of guys such as Coco Crisp or Shannon Stewart, players who injured their arms early in their careers and threw with wet noodles thereafter. The worst throwing arms on current players belong to guys such as Khris Davis and Matt Carpenter, but I wouldn’t call any of them a 20.

Sarris: As easy as it might be to see a plus arm, capturing the tool in the numbers has turned out to be difficult. Before Ultimate Zone Rating, there wasn’t really anything save perhaps outfield assists, and that’s a rare occurrence that doesn’t capture the power of a strong outfield arm — think of all the times a runner won’t run on a crazy good outfield arm, therefore robbing that arm of the chance to throw them out and get an assist.

UZR debuted with an Arm component, which offered the improvement that it captured those relative non-events. Arm is “based on the speed and location of batted balls to the outfield and how often base runners advance extra bases (advances), don’t advance the extra base (holds), or get thrown out trying to advance (kills)” and even includes park factors, according to the FanGraphs website. By Arm, the best outfield arm over the past three years belongs to players such as Eddie Rosario, Kyle Schwarber and Andrew Benintendi.

But there’s still room for improvement. There is no Arm for infielders, for one, and also we’re still using outcomes to try and reverse engineer a metric to measure the tool. In other words, why don’t we just track the damn throws?

Enter Statcast. (Kind of.) While the TrackMan radar technology that powered Statcast was innovative and able to track all sorts of information we’ve had before, it wasn’t able to fully track every throw on the infield and the outfield. So we can tell you that Aaron Hicks threw the hardest outfield throw on record (105.5 mph!) and that the following outfielders have thrown over 101 mph … but we can’t tell you that this list is complete.

The good news is that the new optical tracking system that is debuting this year — HawkEye — should be able to do this for infielders as well as outfielders as soon as teams are playing in their HawkEye-enabled home parks again. The bad news is that we have to sort of guess which players describe the spectrum of arms in the major leagues right now.

80 arm: Eddie Rosario
30 arm: Manny Margot

(Photo of Byron Buxton: Hannah Foslien / Getty Images)