WASHINGTON -- Through the 2016 season, a 25-year-old Mitch Haniger had spent most of his time as a pro baseball player in Double-A or below and only had 34 career games in the majors. In those 34 games, he hit .229/.309/.404. That's not awful for a first stint, but it wasn't good enough for Haniger. He then decided to look at ways to improve his swing. 

He turned to "Be a Hitter" by Bobby Tewksbary (not the former pitcher)

"I read Bobby Tewksbury's book on hitting mechanics and in the offseason going into it I knew what changes I wanted to make. I went with my good friend Daniel Descalso and we worked with a guy named Matt Lisle? out in the Bay Area and he's now the hitting coach for Missouri."

Haniger was pairing the mental side of the game with the physical, as he worked exhaustively in the cages and weight room in the offseason. The result was him having a great 2017 campaign in Seattle, coming over in a deal with Jean Segura. Alas, it was an injury-shortened season, but Haniger hit .282/.352/.491 (126 OPS+) with 16 homers in 96 games. He had proven he was good enough to remain an everyday player in the bigs. 

He still wasn't satisfied, of course. 

"This past offseason I worked with three different hitting gurus," Haniger said. 

And now he's a first-time All-Star. Haniger is hitting .272/.358/.488 (136 OPS+) with 17 doubles, an already-career-high 18 homers and 67 RBI (a career high by 20 already). His walk rate is up, he's hitting better pitches and hitting the ball harder than ever. 

A true student of the game and deep thinker, Haniger doesn't even look at confidence as an emotional thing. 

"I get my confidence through the effort I put in the offseason in the weight room and in the cage."

What's the next goal? To master hitting? 

"I don't think I'll ever be able to truly master hitting, I think Ted Williams might be the only one who ever did," he said. "There's always room to improve and that's what's great about hitting." 

That's a pretty good point. Haniger is no Ted, but he is an All-Star after putting in lots of hard mental and physical work.