Capitals Joel Ward (42) and Mathieu Perreault (85) try to control the puck in the final playoff game against the New York Rangers. (Toni L. Sandys/The Washington Post)

After watching the Washington Capitals lose their seven-game playoff series to the New York Rangers, I’ve been thinking a lot about luck in sports.

Most games and sports are some combination of skill and luck. Board games for little kids, such as Candyland and Chutes and Ladders, are almost all luck. You roll the dice or flip a card, and you move your piece. It doesn’t take much skill.

Some sports involve hardly any luck at all. In swimming, for example, the best and fastest swimmer wins. I’ve never heard a swimmer complain that she lost a race because of bad luck. It’s the same in track. The first runner to cross the finish line in the 100-meter dash wins.

But other games involve more luck. A football isn’t round, so it can take some funny bounces. Remember last season when Robert Griffin III fumbled the ball, but it went right to a teammate and he scored? That was pretty lucky, for RGIII and the Redskins.

A baseball is round, but it can still take some unlucky bounces off the grass. And baseball, like many other sports, is a game of inches. The tiniest distance can be the difference between whether a ball is caught or gets by a fielder.

Now, think about the Capitals-Rangers series. The fifth game went into overtime. A shot by Capitals defenseman Karl Alzner bounced off the skate of a Ranger and went right to the Capitals’ Mike Ribeiro, who smacked it into the net for the winning goal. Good luck for the Caps.

The Rangers won the next game, 1-0. Ranger Derick Brassard scored the only goal when his shot skipped off the glove of Caps defenseman Steve Oleksy and into the net. Bad luck for the Caps.

Even in the seventh and last game, which the Rangers won, 5-0, New York scored a couple of goals when the puck bounced off a tangle of bodies in front of the goalie and into the net.

Adam Oates, the Caps’ head coach, said, “[The Rangers] got a lucky one, and every bounce seemed to go their way after that.”

Of course, it is never only luck. Skill plays a big part in any sport. “Luck is the residue of design,” said Branch Rickey, the long-ago general manager of the St. Louis Cardinals and Brooklyn Dodgers.

He meant that players and teams that have worked hard and prepared for the game usually get the lucky bounces.

I think Rickey was right. But after another disappointing playoff loss, I wouldn’t blame Capitals fans for wondering whether their team needs more luck.

Fred Bowen is the author of 19 sports books for kids. His latest baseball book is “Perfect Game.”