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 Angels heading into the 2017 season.
1. Barrel it up
Since the Statcast™ Era began in 2015, no hitter in baseball has been as prolific in generating hard contact as Michael Trout. The Angels star leads the Majors with 125 barrels -- or batted balls whose combination of exit velocity and launch angle give them a minimum .500 expected batting average and 1.500 slugging percentage -- over the past two seasons.
Most barrels among Major League hitters in 2015-16
1. Trout: 125
2. Nelson Cruz: 123
3. David Ortiz: 115
4. Chris Davis: 114
5. J.D. Martinez: 110
2. A call to arms
With two offseason additions, the Angels' infield is suddenly filled with some of the strongest defensive arms in baseball. New second baseman Danny Espinosa actually led all shortstops for strongest "competitive" throws -- or throws in a player's 90th percentile of effort or higher -- while incumbent shortstop Andrelton Simmons also placed within the top 10.

Meanwhile, new catcher Martin Maldonado led all catchers in average pop time and tied for the fourth-strongest arm behind the plate in 2016.
Highest average "competitive" arm strength (minimum 150 throws from shortstop)
1. Espinosa: 90.7 mph
2. Didi Gregorius: 88.3 mph
3. Jonathan Villar: 88.2 mph
4. Carlos Correa: 87.5 mph
5. Brandon Crawford: 86.5 mph
6. Jorge Polanco: 85.6 mph
7. Trevor Story: 85.5 mph
8. Alcides Escobar: 85.4 mph
9. Simmons: 84.7 mph
10. Brad Miller: 84.0 mph
Quickest average pop time to second base by a catcher (minimum 15 tracked times)
1. Maldonado: 1.91
2. J.T. Realmuto: 1.92
3. Gary Sanchez: 1.92
4. Welington Castillo: 1.93
5. Salvador Perez: 1.94
3. Better luck for King Albert?
Jose Pujols' .780 OPS in 2016 was the lowest in any season of his career in which he played at least 100 games. But some of that figure may have been attributed to bad luck. According to Statcast™ hit rates, which estimate a player's expected numbers based on the exit velocity and launch angle of his batted balls, Pujols actually produced an estimated OPS of .894.

That 114-point gap between Pujols' estimated and actual OPS was the fourth highest of any player with at least 500 plate appearances in 2016. Much of the difference could be attributed to the gap between Pujols' estimated (.544) and actual slugging (.457) percentages.
Largest negative gap between actual vs. estimated OPS in 2016 (minimum 500 plate appearances)

1. Kendrys Morales: -.147 (.795 vs. .941)
   
2. Jose Cabrera: -.142 (.956 vs. 1.098)
   3. Pujols: -.114 (.780 vs. .894)
   
3. Joe Mauer: -.093 (.752 vs. .844)
   
4. Howie Kendrick: -.085 (.691 vs. .776)
   4. Give it a spin
   Right-hander Garrett Richards is attempting a comeback from stem-cell treatment surgery on his pitching shoulder, but regaining the velocity on his fastball is just one step toward returning to his former self. While Richards' average fastball velocity did sit in the mid-to-upper 90s, it was the spin rate on his fastball that separated the pitch from most other heaters in baseball.
   Richards averaged 2,510 rpm on his four-seam fastball in 2015, the most of any pitcher who threw that pitch at least 700 times. That kind of spin elicits more swinging strikes and produce softer contact from hitters, as shown by opponents' 86.6 mph exit velocity against Richards' four-seamer two years ago -- the third-softest contact against any pitcher who induced at least 120 batted ball plays.
   Highest average spin rate on four-seam fastballs in 2015 (minimum 700 pitches)
   1. Richards: 2,510 rpm
   
5. Justin Verlander: 2,500 rpm
   
6. Max Scherzer: 2,498 rpm
   Lowest average opponent exit velocity vs. four-seam fastball in 2015 (minimum 100 batted balls)
   
7. J.J. Hoover: 85.6 mph
   
8. Clayton Kershaw: 85.7 mph
   
9. Johnny Cueto: 86.2 mph
   4. Richards: 86.6 mph
   
10. Trevor Gott: 86.7 mph
    5. Time for a change
    Matthew Shoemaker threw his changeup (also referred to as a split-finger fastball by some) 23.1 percent of the time through his first six starts of 2016 before deciding to make it a focal point of his repertoire. By season's end, Shoemaker had thrown the changeup for 40 percent of his total pitches, which was the highest usage of the changeup among all big league pitchers who threw at least 1,500 pitches last season. In fact, Shoemaker used the changeup a full 8.4 percent more than second-place Chris Devenski of the Astros.
    So, why the change? The answer lies in the contact: Opposing batters averaged an exit velocity of just 85.6 mph against Shoemaker's changeup, which ranked as the fourth-softest contact against any pitcher who induced at least 100 batted balls with the pitch.
    Highest percentage of changeups thrown in 2016 (minimum 500 total pitches)
    1. Shoemaker: 40.0 percent
    
11. Chris Devenski: 31.6 percent
    
12. Marco Estrada: 29.6 percent
    Lowest average opponent exit velocity vs. changeup in 2016 (minimum 100 batted balls)
    
13. Marco Estrada: 82.5 mph
    
14. Kyle Hendricks: 83.2 mph
    
15. David Price: 85.3 mph
    4. Shoemaker: 85.6 mph
    
16. Hector Santiago: 85.8 mph