We've been kicking around the term "five-tool player" for more than 50 years, since legendary baseball executive Branch Rickey first coined the term, and even if you don't know exactly what it means, you know what it infers. It means the best of the best, the rare all-around player who can do everything well. Even when Rickey introduced it in 1965, he could name only two players he felt qualified: Willie Mays and Mickey Mantle. You've heard of them.
Barely more than two months into his Major League career, Indians rookie outfielder Bradley Zimmer is doing things every single night that make us think that he belongs in that category, too. (The "five tool" category, that is, not the Mays/Mantle one. Not yet, anyway.) Every night, he's doing something that passes not only the eye test, but lights up the Statcast™ lab.
First, what is a five-tool player? Traditionally, the five tools are hitting, hitting for power, running, fielding and throwing, though it can get a little subjective from there. Some definitions state that a player must be at least average at all five things, while others prefer a player to be above average in each category. And of course, for years, these definitions all came from scouting reports.
With all the new technology we have at our disposal, we can do better. No, you don't need to be a five-tool player to be a star, as Jose Cabrera (running) and Michael Trout (throwing) will tell you. But it's an extremely good place to start. With some help from Statcast™, here's why Zimmer qualifies.

Running
Earlier this year, we introduced our favorite new Statcast™ metric, "Sprint Speed," which measures runner foot speed in feet per second (in their fastest one-second window). We report the average of a player's qualified maximum effort runs, so we end up with a number where 27 feet per second is league average, and the slowest catchers and designated hitters are down around 23 feet per second. You can see the entire leaderboard here.
When we introduced it, we expected Billy Hamilton and Byron Buxton to be at the top, and they are, tied at 30 feet per second. What we didn't expect was that soon after, a rookie listed at 6-foot-5, 220 pounds would jump onto the leaderboard in third place. Right now, among the 391 qualified players, only baseball's two most obvious speed demons top Zimmer.
Sprint Speed leaders in 2017
30 feet per second -- Hamilton, Buxton
29.7 feet per second -- Zimmer
29.6 feet per second -- Dee Gordon, Raimel Tapia
We knew Zimmer was fast; after all, he stole 44 and 38 bases in the Minors in 2015 and '16, respectively. But we didn't know he was this fast, as most scouting reports had his running as a 55-60 on the 20-80 scale, meaning above-average, but not elite. It's not often you see a player this tall running this fast, we suppose, as he did when he hit 30 feet per second in beating out his first career triple. 

Zimmer knows, it too, challenging Atlanta's famous "The Freeze" to a race. We'll say this qualifies as a tool.
Throwing
This one is almost too easy, because Zimmer has made it easy, and also because Statcast™ takes some of the guesswork out of arm strength. He's only been up since the middle of May, yet Zimmer already has eight of the 18 hardest outfield throws in the bigs this year, including five of the dozen tracked at 100 mph or harder.
Zimmer has the hardest assist of the year, hitting 101.5 mph to nail Max Kepler on June 18.

Zimmer also has the fourth-highest maximum effort outfield arm strength average (minimum five throws), at 97.4 mph, and while we don't even have Statcast™ data on this one from Spring Training, just look at it, off his back foot.

Tool two, checked off.
Fielding
In Zimmer's short time up, he's made more than a few spectacular catches, including this Four-Star (46 percent catch probability) grab against Shin-Soo Choo:

Sometimes Zimmer even does it twice in one day.

This is actually closer than it seems, though, because much of Zimmer's value comes from his arm, which we're rating separately. Setting the arm aside, Statcast™ metrics have his range as slightly above average, while DRS and UZR have him as average.
Still, Zimmer is doing things few have done. Since 1901, only three other players listed at 6-foot-5 have had a season in which they played at least 80 percent of their games as a center fielder, with a minimum of 50 games. William Fowler has done it nine times. Zimmer is doing it now, and doing it well. That's good enough. It's a tool.
Hitting for average
We don't really care about "batting average" here, though if you did, Zimmer's current .284 is still above the Major League average of .255. Instead, we care about making solid contact, about hitting the ball hard -- about exit velocity. That's not just a measurement, it's a skill. For example, Hamilton has one batted ball over 105 mph in the three years of Statcast™, while Nelson Cruz did it three times between Sunday and Monday. Hamilton is gifted in many ways, just not in this way.
So how do we define being above average here? We like to use 95 mph as the cutoff for a hard-hit ball, and the Major League hard-hit percentage is 33 percent. Zimmer, on the other hand, is well above that, at 43 percent; of the 263 hitters with as many batted balls as he has, that's 37th, or the top 15 percent. Only 43 hitters have had a ball hit at 114 mph, as Zimmer did off Sonny Gray in May, and over 800 have stepped to the plate.

Hitting for power
There's obviously some overlap with hitting in general here, and you can't get power without exit velocity. Zimmer's expected to be more solid-average in the power department than a 40-homer slugger, with a 20/20 season more likely than a place in the Home Run Derby.
Still, a 20-homer season is more than most hitters get, and with eight in 261 plate appearances so far, that's about where Zimmer would end over a full season. How about distance? Zimmer's longest dinger so far was a 435-foot grand slam off Jesse Chavez last week; his second was a 424-foot blast off Detroit's Chad Bell on July 7.

The average home run this year has gone 401 feet; Zimmer's is 412 feet. The average non-grounder (i.e., ball in the air) has gone 275 feet; Zimmer's is 276 feet. It's probably not fair to say he's a "plus" power hitter, but at the very least, he's average here.
Based on what we've seen so far, it seems pretty fair to say we're watching a five-tool player. Zimmer is not the only one; you could probably make arguments for Kristopher Bryant, Bryce Harper, Mookie Betts and others. Zimmer might be the most unexpected one, however. Players this big shouldn't be this fast, and they shouldn't play center. If not for Aaron Judge, we'd be talking about an American League Rookie of the Year Award candidate. Instead, we're talking about a Cleveland building block -- and a five-tool player.