The biggest single reason Stephen Strasburg lost his fourth straight start on Wednesday as the Washington Nationals fell below .500 is because he won’t throw “strike one.” He can. But he doesn’t. He says he will. Then he backslides. He talks about pitching to contact, quick outs, efficiency and going deep in games, then does the one thing that negates all of it: “Ball one.”

“I was trying to throw the perfect pitch. I tell myself, ‘Don’t do that.’ Then I go out there and do it,” a disgusted Strasburg said of a three-run first inning in a 4-2 defeat to the St. Louis Cardinals. Falling behind hitters and “trying to do too much” has been Strasburg’s recurrent complaint against himself through the first four-game skid of his career. But then he does it again.

Strasburg fell behind four of the first five Cards hitters, had to throw strikes on the hitter’s terms and saw the game lost when it had barely begun. The worst thing a team in a hitting slump can endure is an early deficit before it even gets to bat. Asked to be an ace, Strasburg dealt a trey.

The Cards’ rally was built on a walk and two opposite-field chunk hits dumped in front of outfielders. “You saw it. Weak contact, what can you do,” Strasburg said. Most pitching coaches of the last 100 years would say, “Throw strike one.” Then hitters will not get a free chance to look for a specific pitch in a particular zone and drop an ugly duck snort over the infield.

In 2011, Strasburg threw first-pitch strikes 71.6 percent of the time, the highest in baseball. He carried over his “challenge” mentality from college and put fear of shame into hitters. Last year, he threw 62.3 percent, 34th among starters. Wednesday, he was down to 56.2 for the season, an awful 84th among 107 starters.

How can the pitcher with, perhaps, the best four-pitch stuff of his generation — any one of which he can use to challenge hitters with arrogance if not impunity — shy away from contact on the pitch which, if it’s a strike, opens the door to outs? Every year, the average on-base-plus-slugging percentage in MLB is more than 100 points lower after 0-1 counts than 1-0. Everything else in pitching is hard. “Strike one” is lesson one on day one.