Sometimes -- most of the time, perhaps -- you know when you see a great outfield play, because you know what a great outfield play is supposed to look like. When Kevin Kiermaier made this fantastic diving catch to rob Jackie Bradley Jr. in September, you instantly knew it was great. When Austin Jackson flipped over the Fenway Park wall in right to steal a homer from Hanley Ramirez, you knew right away it was a catch we'd be talking about for years.
That's all well and good, usually. But the thing about tracking down outfield flies is that sometimes, if an outfielder is skilled enough, he can make a truly fantastic play without needing to make it look impressive. We've always known that a below-average outfielder can create some great-looking diving catches because he was too slow or he took a poor enough route to make the dive necessary; why can't we credit the guys who are so good that they just got there and made it look easy? 
Let's do that right now with four of the best catches from 2017 that you might not have noticed, because without a dive or a leap, they likely didn't make highlight reels. The reason we know they're great is thanks to Catch Probability, the Statcast™ metric that looks at how far a fielder had to go, how much time he had, and in what direction, and lets us know how often that opportunity is made across the Majors.
The probability of the Kiermaier catch, for example, was 18 percent, meaning that eight out of 10 times an outfielder gets a similar opportunity, he doesn't get there. It looked great, visually. It looked great, data-wise. Here are four of our favorites from 2017, where a great play was made to look easy -- and we'll show you just how great it was by comparing it to an identical play that led to a dive or a non-catch.
Byron Buxton, 18 percent, Sept. 10

Jankowski: 111 feet away, 5.3 seconds of opportunity time. Buxton: 112 feet away, 5.4 seconds.
We had to start with Buxton, obviously, because baseball's fastest man is also baseball's best outfielder. Sometimes, that leads to fantastic-looking diving catches, like when he laid out for a 24 percent catch to rob Jason Kipnis in September. (For all those who insist 24 percent is too high and that no one else makes that play: Allow us to introduce you to Manuel Margot.)
But sometimes, that turns into Buxton's elite speed allowing him to take away extra bases without needing to leave his feet, like when he needed to run across half the state to take away this drive off the bat of Salvador Perez. That's a nice-looking catch; even a fine-looking one. Does it give you the same reaction as when Travis Jankowski made a great sliding catch to rob Adrian Gonzalez in 2016?
Probably not, but that's the point. Buxton needed to go 112 feet in 5.4 seconds; Jankowski needed to go 111 feet in 5.3 seconds. They started at essentially the same distance from the wall. They went in the same direction. For all intents and purposes, this was the same play, which is why Jankowski had a similar 20 percent Catch Probability. Buxton just made it look easier.
Billy Hamilton, 24 percent, July 18

Blackmon: 68 feet away, 4.0 seconds of opportunity time. Hamilton: 71 feet away, 4.1 seconds.
Because elite speed is such a vital part of getting to a tough play and making it look easy, you knew that Hamilton was going to end up here, and he was basically tied with Buxton atop the Sprint Speed leaderboards. While it's certainly not like Charlie Blackmon isn't speedy as well, the enormous difference in Sprint Speed on this play -- 31.4 ft/sec for Hamilton, 27.8 ft/sec for Blackmon -- tells the entire story. Hamilton just got there so, so much faster.
Since they were a nearly even distance away from the ball at the time the batter made contact (Hamilton was slightly farther), we can illustrate that by showing how far away they had run from their starting point at one second, two seconds, and three seconds after the ball was hit.
Hamilton
+1 second: 15 feet traveled
+2 seconds: 36 feet
+3 seconds: 67 feet
Blackmon
+1 second: 8 feet traveled
+2 seconds: 25 feet
+3 seconds: 50 feet
Speed isn't the only thing that makes for a great outfielder, but it makes everything so much easier.
Keon Broxton, 18 percent, June 14

Broxton: 67 feet away, 3.9 seconds of opportunity time. Taylor: 62 feet away, 3.7 seconds.
Broxton's hoped-for offensive breakout didn't materialize, as he hit just .220/.299/.420 for Milwaukee, but he did find himself just outside the Top 10 in Outs Above Average, the Statcast™ range-based outfield metric, in part because he was rated as one of the 10 fastest players in the game. Broxton's Sprint Speed was 29.5 ft/sec, well above the Major League average of 27 ft/sec.
We saw that in action when he tracked down a Jose Martinez liner, making what seemed to be an otherwise ordinary looking catch that you'd probably never think about again. That's a catch that happens 10 times a night, right? But the fact that you think that is a credit to Broxton, who ran an essentially perfect route -- he was 67 feet away, and that's exactly how many feet he ran -- with his usual above-average speed.
The play we're comparing it to here, a Michael A. Taylor dive in May, was also an 18 percent play, and more or less the same opportunity. But Taylor ran a slightly less efficient route, running 65 feet when he needed to go 62, and he had to lay out to make a catch that looked better, even if the opportunity was the same.
Adam Engel, 8 percent, Sept. 28

Span: 81 feet away, 4.4 seconds of opportunity time. Engel: 82 feet away, 4.5 seconds.
Sometimes, a great play is so difficult that it's actually hard to find a completed catch to compare it to, because the same kind of catch is barely ever made. That's the case with Engel's 8 percent Catch Probability snag off of an Jose Pujols liner, because the play we chose to compare it to was a Mike Moustakas drive that Denard Span never came close to getting. The fact that Engel got there at all, much less made it look easy, should tell you a lot.
Now, there are a few things to keep in mind here. First of all, Engel ranked extremely well in our defensive metrics, placing in the top five in Outs Above Average, in part because he was tied for being the 10th-fastest player in baseball. Second, this catch is actually a lot more difficult than it looks, because he was going straight back -- and we know that going back adds difficulty, so we've accounted for that in Catch Probability.