The most beautiful -- or frustrating, depending on your perspective -- part of baseball is that sometimes you can do your job as a hitter nearly perfectly and have it backfire. Sometimes, as has happened to Carlos Gonzalez twice in the past two seasons, you can destroy a ball at 117 mph off the bat and have it turn into an out, because of defensive placement or lack of height or just plain bad luck. Doing exactly what you want at the plate doesn't always lead to success. It's hard to reconcile, sometimes.
As we dig deeper into Statcast™ data, we can get a lot closer to understanding what types of batted balls are the most likely to become hits, at least based on the combination of exit velocity and launch angle. We know that those two data points form a crucially important marriage, because where you place a ball is just as important as how hard you hit it. To choose a random example, all balls hit at 63 mph have just a .199 batting average, because those are not well-hit balls. However, balls hit at 63 mph with a 35-degree launch angle have a .917 batting average, because they can get over the infield but fall in front of the outfield.
With that in mind, we can identify the batted balls so far this season that had the highest likelihood of becoming hits, but turned into outs anyway. It turns out that there's actually a few different causes, from defensive positioning to ballparks to bad luck, but the main unifying factor is a hitter who walks away completely disgusted with what just happened. It's the kind of thing only baseball can offer.

  5. May 3, Seattle @ Oakland -- Seth Smith lines out into the shift
77 mph / 19 degrees / 36 hits in 37 instances

There's a lot of reasons why it's harder than ever to be a hitter. Velocity keeps going up, and the strike zone seems to keep increasing at the bottom. An endless supply of fresh one-inning relievers come out of the bullpen to whip sliders and cutters at speeds that previous generations could never have imagined.
And sometimes, it's because you hit a ball that lands safely for a hit 36 times out of 37, as Smith did in Oakland earlier this month, and the second baseman is standing where no fielder traditionally had any business whatsoever standing. Just look at where Jed Lowrie was lined up before the previous pitch:

For more than a century of baseball, and even for most of present-day baseball, putting a batted ball in that spot would be guaranteed success. So file this one under "why teams shift," because the A's had Smith pegged perfectly, as you would expect against a hitter who has gone to the opposite field a career-low 17.2 percent of the time this year. That's a big open space of welcoming green grass, suddenly filled by a man with a glove. 

 4. April 25, Oakland @ Detroit -- Billy Burns flies out to center
87 mph / 14 degrees / 43 hits in 44 instances

"It looked like a hit off the bat," suggested the Oakland television broadcast, "but Anthony Gose plays shallow," and they were right. Every other time this year we've seen a batted ball with a combination of 87 mph exit velocity and 14 degrees launch angle, it has been a hit, because that's generally a low liner that doesn't stay up long enough to get to the outfielder. When Jose Altuve did exactly this in Fenway Park earlier this month, it was a ball that bounced twice before it got to the fielder.
In Burns' case, Gose caught this ball 272 feet away from the plate. This year, as last, the shallowest center fielders in baseball stand about 300 feet from the plate. Last year, Gose was one of baseball's shallowest center fielders, at an average of 303 feet away, and while he's moved back some this year, he only had to run 44.3 feet to catch this one.
For context, Gose has ran more than 100 feet to make an out twice this year, and has gone 45 feet or more 43 times. Most times, this is a hit for Burns. Most times, the center fielder isn't right there.

  3. April 6, Colorado @ Arizona -- Paul Goldschmidt lines out to shortstop
92 mph / 11 degrees / 44 hits in 45 instances

Goldschmidt isn't off to a season that's up to his usual standards, and plays like this don't help. Of the other 44 times this particular batted ball had happened, 40 of them went at least 200 feet, which is to say that they were hard line drives at a high enough launch angle that they made it over the infield. Ninety-three percent of the time, this kind of batted ball becomes a single. A few were doubles. Goldschmidt's, and his alone, was an out.

That this ball didn't get past the infield is thanks to Rockies shortstop Trevor Story, who had pretty much everything going in his favor. With the right-handed hitter up, Story didn't need to worry about covering second base on a possible steal attempt, allowing him to move quickly to his right, and though the ball reached a maximum height of 10.5 feet, it was already sinking by the time it got to him. Mostly, though, this was a case of being in the right place at the right time, and making a nice play on it.
Let's go now to a look at Goldschmidt's reaction upon seeing he'd been robbed of a hit:

Unfortunately for Goldschmidt, it wouldn't get better: The very next week in Denver, Story would rob him again on a very similar liner to short. When things don't go right, they never go right.

 2. April 15, Toronto @ Boston -- Josh Donaldson gets eaten up by Fenway
106 mph / 27 degrees / 46 hits in 47 instances

Donaldson hit this ball 106 mph, and most of the time, that's more than good enough. He's hit 25 homers since the start of 2015 that weren't hit as hard as this blast to center off of Rick Porcello.
So maybe you're thinking this is about the brilliance of Jackie Bradley Jr. ,who is also a highly-regarded defensive outfielder in addition to being the owner of baseball's longest active hitting streak. But while Bradley did make a nice play, running 102 feet to track this one down, he's run further for four other outs this year alone, so it's not just about that.
Instead, this one is all about the ballpark, and Donaldson's relative lack of luck that put this one into Fenway Park's famous center-field triangle. Let's map the landing spot of this one onto Fenway's dimensions to show you just how badly placed this ended up being for Donaldson:

If Donaldson had put that just about anywhere else, it's an easy dinger. Compare that to the other four stadiums in the American League East, where this ball is either almost certainly a home run or gives the fielder a lot less breathing room from the wall to deal with:

That's where batted ball direction really comes into play, because if Donaldson had hit this down the lines, or really anywhere other than dead center, that's a home run. That's the necessary third dimension that joins exit velocity and launch angle, and as enough data accumulates for it to become useful, it's how we'll improve these expected outcomes even further.
That's likely cold comfort for Donaldson, however, because those bases would have been extremely useful in a game the Blue Jays would end up losing 5-3. 

  1. May 19, Toronto @ Minnesota -- Troy Tulowitzki gets robbed by Danny Santana
107 mph / 24 degrees / 47 hits in 48 instances

It's not hard to understand why 107 mph at 24 degrees comes with such high likelihood of success. Batted balls above 105 mph in the Statcast™ era, at any angle, fall for a hit 70 percent of the time (.706 batting average). Batted balls between 20 and 30 degrees of launch angle are right in the line drive zone. Combine the two and, well, you can see where that 47 for 48 is coming from. You can pretty easily turn this combination into a homer, as Eugenio Suarezdid toKyle Lobstein.
For Tulowitzki, it was the perfect storm of bad luck, because not only did he hit it just under 400 feet to a part of Target Field that can accommodate a ball that deep, he hit it to converted shortstop Danny Santana. As of May 20, Santana was playing one of the deeper center fields in baseball, at an average of 315 feet, but he's also proven himself to be one of baseball's fastest players. We can use Statcast™ to measure home-to-first running times as a measure of foot speed (we explained our methodology to eliminate non-competitive plays here) and so far this year, with a minimum of 25 tracked plays, Santana's average home-to-first time of 3.9 seconds is second only to Billy Hamilton, ahead of Dee Gordon and Burns. 
That's impressive company to be in, and suddenly the pieces make sense. Tulowitzki needed to hit this to the wrong part of the field where a deep center fielder with elite speed was playing, and that center fielder had to actually make the play.