has an interesting article on the psychology of baseball. Here is an excerpt:

“Beane was just sort of crushed by the pressure of the batter’s box, just didn’t have that sort of self-confidence, almost arrogance, just to know, ‘I do this well. I’m fine. So what I just struck out, I’m going to hit next time,'” Stadler said.

Strawberry displayed the exact opposite reaction: “You can look at some of Strawberry’s early interviews when he broke into the league and was struggling a little bit as player’s naturally do, but he, even then he just said, ‘I know I’m a good hitter. I’m going to hit plenty of home runs,'” Stadler said. “He just wasn’t worried about the pressure.”

What makes up what Stadler calls a “baseball personality” like Strawberry’s was described by personality test called the Athletic Motivation Inventory (AMI) developed by William Winslow, still used by many baseball teams today to sort out which players have the personality traits it takes to succeed in major-league baseball.

The traits that seemed to be most important in baseball were some of the ones Strawberry clearly displayed: self-confidence, mental toughness (or how well a player rebounds from failure), emotional control in stressful situations and a slight tendency toward aggression (in this context, the desire to make things happen).

Strawberry’s self-confidence and mental toughness are particularly apparent in his comments and are critical traits in a major-league hitter.

“If you’re a hitter, you fail two-thirds of the time, so you can imagine why self-confidence would be really important,” Stadler said. “You have to keep, sort of keep plowing through, even though you just struck out four times in a game or something”