5 Statcast storylines for '17 Astros

March 31st, 2017

As the 2017 season begins, so does the third season of Statcast™, the state-of-the-art technology that has tracked every play in every Major League ballpark since Opening Day 2015. And with two full seasons of data now collected, plus advances in applying that data, Statcast™ is better than ever. New metrics, such as Catch Probability and Hit Probability, will provide a deeper layer of analysis and further our understanding of the game.

With that in mind, here are five Statcast™ storylines to know about the Astros heading into the 2017 season.

1. Double barrel

captured his second American League batting title in 2016, but he did so as a very different hitter than when he won his first two seasons before.

Altuve boosted the power in his swing last year by being more selective in the pitches he swung at and lifting his launch angle. The result? A significant uptick in average exit velocity and a barrel rate (batted balls whose combination of exit velocity and launch angle yield an expected batting average of at least .500 and an expected slugging percentage of at least 1.500) that nearly doubled in the span of one season.

One could see the power surge right on Altuve's stat sheet, as his OPS jumped 116 points from 2015 to '16.

2015

Chase percentage: 38.2 percent

Average exit velocity: 86.1 mph

Average launch angle: 9 degrees

Barrels/PA: 2.6 percent

2016

Chase percentage: 35.0 percent

Average exit velocity: 88.7 mph

Average launch angle: 11 degrees

Barrels/PA: 5.0 percent

2. Super sliders

Houston's bullpen contains not one, but two of the very best sliders in baseball. The tandem of and Luke Gregerson recorded the second- and third-highest swing-and-miss rates on sliders out of all pitchers who threw the pitch at least 250 times last season. Giles and Gregerson were also the very best at getting hitters to swing and miss at sliders out of the zone.

Highest whiff rate on sliders in 2016 (minimum 250 sliders thrown)

  1. : 35.0 percent

    2. Ken Giles: 34.2 percent

    3. Luke Gregerson: 32.6 percent

  2. : 28.8 percent

  3. Max Scherzer: 28.0 percent

    Highest whiff rate on out-of-zone sliders (minimum 250 thrown)

    1. Ken Giles: 41.1 percent

    2. Luke Gregerson: 40.4 percent

  4. Max Scherzer: 33.4 percent

  5. Noah Syndergaard: 32.7 percent

  6. : 31.8 percent

    3. Not "short" on power

    Shortstop is not a position at which power hitters have typically been found, but last season saw a slugging explosion from shortstops that was led in part by . At age 21, Correa led all shortstops in average exit velocity on batted balls in 2016.

    Highest average exit velocity for SS in 2016 (minimum 100 batted balls)

    1. Carlos Correa: 91.8 mph

  7. Brad Miller: 91.7 mph

  8. : 91.5 mph

  9. : 91.5 mph

  10. J.J. Hardy: 91.0 mph

4. Shining star

Catch Probability shows how likely an outfielder is to make a particular catch based on how far he needs to travel and how much time he has to do so. The new Statcast™ metric showed off 's talent in the outfield last season, when he snagged the fourth-most "5-Star" plays (Catch Probability of 0-25 percent) and recorded the fourth-best success rate on converting "4-Star" plays (Catch Probability of 26-50 percent).

Most successful 5-Star plays in 2016

1-T. : 10

1-T. : 10

3. Billy Hamlton: 9

4. Jake Marisnick: 8

5-T. : 7

5-T. : 7

5-T. : 7

Highest success rate on 4-Star plays in 2016

  1. Steven Souza Jr.: 91.7 percent

  2. : 88.9 percent

  3. : 87.5 percent

    4. Jake Marisnick: 80.0 percent

    5-T. : 75.0 percent

    5-T. : 75.0 percent

5. Out of sync

Houston ace identified pain in his left pitching shoulder as a major reason why he regressed from a Cy Young Award-winning season in 2015 to a 9-12 record and 4.55 ERA for the Astros in '16. Keuchel's discomfort was evident in the dip in velocity on his signature pitch -- the two-seam fastball -- and the kind of contact he was giving up with it.

Two-seam fastball in 2015

Average velocity: 89.9 mph

Average exit velocity allowed: 86.5 mph

Barrels/Batted Ball Events: 0.5 percent

Two-seam fastball in 2016

Average velocity: 88.8 mph

Average exit velocity allowed: 92.0 mph

Barrels/BBE: 3.8 percent