When Eddie Rosario broke into the major leagues in 2015, speed was a big part of his game. By StatCast's measurement, he was among the speediest 13% of the league's players. He had stolen 22 bases in 51 games in rookie ball in 2010 and had double digits in every minor league season, and once in Minnesota he became the first rookie since Ray Lankford in 1991 to lead the majors in triples.

But Rosario doesn't steal bases anymore — he's got three this season, and none since he sprained his ankle in late June — and there's simple reason for it.

"It's better," Rosario said with a smile, "to [trot] around the bases than to run."

Yes, a predictable side effect of baseball's home run explosion is the rapid obsolescence of stolen bases, and no team illustrates the transformation better than this year's Twins. They have already blown past the 1963 Twins' franchise record for home runs, en route to possibly becoming the first major league team ever to hit 300 in a season.

The 1963 Twins set another franchise record, too, one that this year's version might also smash: fewest stolen bases. Those Killebrew-Allison Twins swiped just 32 bases, a number that appears more impregnable by the day, as the current Twins' pursuit slows to a crawl. The 2019 Twins have stolen 26 bases all year, just two in August, and only three since the All-Star break six weeks ago. They led the AL in steals as recently as 2012 — the days of Ben Revere, Alexi Casilla and Denard Span — but appear likely to finish 30th in MLB this year.

"Stolen bases are an exciting part of the game, and there's certainly a place for them," said Twins manager Rocco Baldelli. "But it's not something where a lot of teams are forcing the issue at this point [because] it's become more and more difficult to run."

There are a number of reasons for the Twins' station-to-station approach:

• Slow players. It's blunt but accurate — the Twins have one elite speedster in Byron Buxton, a handful of players like Rosario, Jorge Polanco and Max Kepler with average speed, and several bulky sluggers who should never try to steal a base. Minnesota is successful on only 56.5% of its steal attempts, worst in the majors and the franchise's lowest conversion rate since 2002.

• Buxton's injury. The center fielder stole 29 bases two seasons ago, and built a streak of 33 consecutive successful steals that ended in April. But he's played only 82 games this season due to a series of injuries, severely damaging the Twins' running game. "You play according to your personnel," Baldelli said. "If you had five Byron Buxtons running around the field, you would steal a lot of bases."

• Injury risk. "When you run a lot, you can get hurt," Rosario said, pointing out that his severe ankle sprain occurred when he slipped on first base.

• Defense. "Years ago, not every pitcher had a slide step. If you could get a good jump, you could take a base," Baldelli said. "There aren't many pitchers that are regularly [slow] to the plate anymore. Pitchers pay a lot of attention to it, and a lot of guys have pickoff moves that probably push the limit of what is legal. It's become very challenging for base-stealers."

• But all of those reasons are probably minor next to the biggest one: home runs. The Twins score a record 51% of their runs on homers, so every baserunner lost to an unsuccessful steal is a runner who can't trot home when the ball clears the fence.

"We have to be safe at least 75 percent of the time for the gain of a base to be worth the risk of being thrown out," said third base coach Tony Diaz. "But our lineup has home run hitters one through nine, so it's not a good risk for us."

Or most good teams, actually. The top five home run-hitting teams in the majors this year all lead their respective divisions; the highest division leader, entering the weekend, among the stolen-base leaders is Atlanta, ranked 10th. Stolen bases are on pace to total about 2,250 in the majors this season, fewest in a full season since 1972, when there were only 24 teams.

And stealing third base? Don't even think about it. The Twins have done it once, back on May 27, when Luis Arraez took advantage of a defense playing out of position.

The Twins might yet swipe a few more bases this year, though. Buxton figures to return in a week or two, and the Twins acquired minor league speedster Ian Miller, who has stolen 30 or more bases in five straight seasons, from Seattle earlier this month. Might he be added as a pinch runner for a big situation down the stretch?

Baldelli wouldn't comment on Miller specifically but said: "There are times when one base might make a difference in a late-inning situation. It's something we've talked about, the value of having someone who could get that base for you."

Other than that, though? "The reality is, for us, for a lot of teams, trying to run just to be stealing bases isn't worth it," Baldelli said.

Phil Miller covers the Twins for the Star Tribune. Twitter: @MillerStrib.

E-mail: phil.miller@startribune.com