The first four days of the 2018 MLB regular season are in the books. Only four teams remain undefeated (Chicago White SoxMilwaukee BrewersPittsburgh PiratesWashington Nationals) while four are still looking for their first win (Cincinnati RedsDetroit TigersKansas City RoyalsSan Diego Padres). The early batting average leader? Seattle Mariners outfielder Mitch Haniger. He is 5 for 8 (.625).  

April is simultaneously the best and worst time of the year for baseball analysis. It's the best because baseball is back! Spring training is fun in its own way, but there's nothing quite like meaningful baseball. It's also the worst because everything that has happened so far has happened in a small sample size. An extremely small sample size. Tough to know what is part of a trend and what is simple randomness. That's never stopped us before though, and there's no reason it should stop us now. 

Here is just one our 10 early season observations.  

The fly ball revolution is alive and well

It's never too early to look at league-wide trends. Individual player numbers may not mean much after four days, but we already have nearly 4,000 plate appearances worth of data across MLB. Here are some league averages:  

Launch Angle

Ground Ball Rate

Strikeout Rate

2015

10.1°

45.3%

20.4%

2016

10.8°

44.7%

21.1%

2017

11.1°

44.2%

21.6%

2018

13.4°

40.4%

22.1%

Launch angle and the so-called fly ball revolution is all the rage now. Hitters are trying to get the ball airborne because balls hit in the air are more likely to go for extra-base hits. More and more hitters are adopting an uppercut swing, even a slight uppercut, and that isn't necessarily conducive to contact. It is conducive to hitting for power though.

In the super early going this year, the recent trend has continued. Launch angles are going up, ground ball rates are going down, and strikeout rates are going up as well. This is not some new temporary fad. This is where baseball is heading. Hitters are trying to get the ball in the air more often with each passing season, and by and large, they're succeeding.