MLB playoffs 2023: How the year of the stolen base could transform the feel of the 2023 postseason

On Wednesday, as the Chicago Cubs pressed at maximum intensity, trying to secure one of the National League’s final postseason berths, Atlanta Braves superstar Ronald Acuña Jr. pilfered second base, ripped it out of the ground and hoisted it above his head to celebrate his 70th steal of the season. Then he promptly raced home on an Ozzie Albies single to hand the Cubs a crushing defeat.

It could’ve been mistaken for an MLB executive’s fever dream circa one year ago. When the new rules for 2023 were announced, the goals were clear: Make baseball games quicker, and inject more athletic action. Acuña’s jaw-dropping individual output — his 73 steals are the most in a single year since Jose Reyes nabbed 78 in 2007, plus the whole “he also hit 41 home runs” thing — has been a compelling Exhibit A for this livelier, more kinetic version of baseball.

A broader inspection also supports the idea that the rule changes worked. The pitch clock, the related pickoff restrictions and slightly bigger bases combined to produce a spike in stolen bases. Runners attempted more steals (0.90 per team game) than in any season since 2011 and successfully swiped more bags (0.72 per team game) than in any season since 1997. No team had stolen 150 bases in a season since 2016, but five eclipsed that mark this year, with young teams such as the Arizona Diamondbacks and Cincinnati Reds finding identities and surprising levels of success in their aggression.

Now, MLB’s recalibration efforts are about to be put through a more grueling test under brighter lights. The postseason, as The Ringer’s Ben Lindbergh wrote in 2018, has become something like the ghost of baseball future. Bullpen dominance, rising fastball velocities, overwhelming strikeout numbers, homer-centric scoring and other tides that reshaped the game? They all showed up in the playoff pressure-cooker before reaching the sport’s every-day iteration.

“In October, teams collectively take existing trends to extremes,” Lindbergh wrote, “both because playoff clubs often embody the latest and greatest ways to be good at the game and because the postseason schedule permits much more aggressive strategies than the six-month marathon that precedes it.”

Accentuated by national broadcasts and focused collective attention, those supercharged trends sometimes became something for baseball fans to lament or flat-out dread — a second-hand embarrassing experience, like terrible service at the restaurant you dragged all your friends to. Eventually, postseason baseball’s stagnant tendencies — too many strikeouts, too few balls in play, too many minutes spent watching pitchers dawdle on the mound between 98 mph heaters — served as the loudest alarm bells that change was necessary.

This year, then, marks a departure. With at least one prevailing trend, MLB has something to anticipate, not gird against. If the new rules amped up the stolen base landscape this much in the regular season, will the postseason be a further accelerant?

What is driving MLB’s stolen base surge?

Earlier this month, the Diamondbacks declined to hold on New York Mets pinch-runner Tim Locastro at first base. Up 4-3 with two outs in the ninth inning, Arizona had closer Paul Sewald on the mound with the tying run on third and Brandon Nimmo up to bat. Manager Torey Lovullo’s decision to play first baseman Christian Walker behind Locastro, effectively conceding the steal, flummoxed Mets broadcasters Gary Cohen and Keith Hernandez and set off a minor war of words.

Arizona pitching coach Brent Strom said he thought the broadcasters were “idiots” for their take on the strategy. Whatever you think of the maneuver — the D-backs got Nimmo to fly out and won the game — Strom’s reasoning was instructive and blunt.

“I thought it was a very smart move,” he said two days later, “because we weren't going to throw Locastro out.”

By the D-backs’ calculations, the risks of trying to counter the attempted steal (leaving an infield hole on a left-handed hitter’s pull side, potentially throwing the ball away, potentially allowing the runner on third to break for home) were greater than their chances of preventing a fast runner from taking second.

The league-wide success rate on steal attempts is 80% this season, up from about 75% last year and a new high-water mark in MLB history. That makes it sound as though it’s easier to steal a base in 2023, but that’s not exactly the case. The more precise way to describe what’s happening is that the rule changes have tilted the scales so that more base-stealing opportunities meet teams’ rigorous risk-reward standards — while bold efforts at tamping down the running game often don’t.

This is, in large part, a matter of pure physical distance. Statcast shows that the average runner attempting to steal second in 2023 was almost a full foot closer to his destination than in 2022, which owes a smidge to bigger bases but is mostly a product of emboldened runners. Pitchers can throw over (or disengage from the rubber in any way) only twice per plate appearance, unless they want to risk an automatic balk by trying for a sneak-attack out on the third attempt. Holding down the running game is now mostly a matter of altering timing.

“We constantly have to remind the guys to hold the ball, to change their cadence,” Strom said.

Catchers, even with the data showing faster exchanges and harder throws, have little hope most of the time. This year, they cut down only 19% of attempts at second, though a few outliers, such as Arizona’s Gabriel Moreno, have shown that success is possible — and perhaps more attainable for younger backstops more familiar with and responsive to the constraints of the new rules. With lightning-fast exchanges and incredible accuracy, the 23-year-old in his first full season threw out 48% (16 of 33) of runners attempting to steal second. Texas Rangers catcher Jonah Heim and Seattle Mariners catcher Cal Raleigh also logged impressive caught-stealing rates around 30%.

Overall, though, there is less hesitation, less cause for pause, when a runner wants to take off. Elite speedsters and simply savvy runners can steal almost at will this year. Philadelphia Phillies shortstop Trea Turner stole 30 bases without being caught, a decisive new major-league record. At 34 years old, Los Angeles Dodgers star Freddie Freeman obliterated his previous career high with 23 steals, all with only one caught stealing. Diamondbacks outfielder Corbin Carroll, the likely NL Rookie of the Year, tallied 54 steals and was caught only five times, a 92% success rate when the breakeven mark has typically been pegged at 75%.

Will MLB’s best run when it really counts?

It’s not happenstance, of course, that the generally agreed-upon mark for efficient stealing came to mirror the league’s overall success rate. Often, teams value a man on the bases too much to risk an out for advancement — and certainly too much to risk an out for the chance of doing something cool and fun.

That ties into the persistent tug of a different trend: Power is the name of the game, the prevailing way to score today, and the players on the field are mostly selected for that ability.

“It’s not that no one runs anymore in baseball,” baseball researcher Russell A. Carleton wrote recently at Baseball Prospectus. “It’s that the game has moved away from running and toward just trying to smack the ball as hard as possible. The players are bigger, and whether or not they are less mobile, they certainly aren’t moving as much as they once did.”

Even with all the running in 2023, the actual thrust of winning and losing MLB games still revolves around the home run. According to a Baseball Prospectus statistic that tracks the percentage of runs that come on homers — dubbed the Guillen Number in winking honor of Ozzie Guillen’s homer-reliant White Sox teams — 41.1% of this season’s scoring came on the long ball. That’s up from 2022 (39.9%) and reminiscent of 2016-2018, not the 1980s halcyon days of small ball.

Looking ahead, that percentage almost always ticks up once the postseason begins. Postseason scoring has been more reliant on homers than the regular season in every year since 2014, and on two occasions (2017, 2020), more than half of a postseason’s entire run total was attributable to homers. Last year, 47.1% of playoff runs came on homers.

Here comes the related news: Stolen base attempts tend to drop in the postseason. A bit of that is tied to on-base percentage, which is noticeably lower against the heightened pitching talent of October. In the previous 10 completed regular seasons, MLB has averaged 0.7 steal attempts per team game — which means you, as a viewer, would likely see three total runners go every two games — but only 0.5 steal attempts per postseason team game, or one per viewing experience.

Still, this season’s boost has changed the math enough that an increase in stealing will probably carry over to the playoffs and maybe even be turbocharged by the added stakes.

Sky-high success rates should lead to more runners going in big moments against daunting pitching, and there’s evidence to provide hope for that idea. For one, September produced more attempts per game than any other month this season.

• March/April: 0.893 SB att/gm, 79.31% success rate

• May: 0.889 SB att/gm, 79.95% success rate

• June: 0.940 SB att/gm, 78.72% success rate

• July: 0.853 SB att/gm, 80.51% success rate

• August: 0.838 SB att/gm, 82.87% success rate

• September: 0.977 SB att/gm, 79.88% success rate

But perhaps the most important factor that might juice postseason steal attempts? The daunting pitching itself. Relievers are more prevalent in October, and they’re worse than starters at containing the running game. Here’s how the split looked this year:

• vs. starters: 77.08% success rate

• vs. relievers: 83.84% success rate

This dynamic is beginning to feel true, too. Teams jostling for postseason position (or their playoff lives) seemed to lean into the running game more. In the final days of the season, there were crucial and daring steals in games with playoff implications.

The Cubs, victims of Acuña’s steal Wednesday, executed a double steal earlier this month against the Diamondbacks — who, you’ll remember, employ the game’s most accurate catcher this season — and earned a run on a throw that got away (though they wound up losing the game).

The Diamondbacks, boasting one of MLB’s fastest rosters, pulled off the same trick just three days later in a huge matchup against the San Francisco Giants, with winning results.

Earlier in September, the Tampa Bay Rays were trailing 1-0 in the bottom of the ninth in a matchup with the Mariners. After getting hit by a pitch, Luke Raley attempted to steal second. Raleigh threw him out, helping preserve a Mariners win that mattered right up until the season’s final moments.

In yet another example, even without technically attempting to run, the steal-averse Rangers lured Toronto Blue Jays pitcher Chris Bassitt into a high-leverage trap by having Mitch Garver stroll halfway down the third-base line when Bassitt had already used his two disengagements.

Scoring on a single after taking a walk? That’s a sequence managers can shoot for persistently in 2023. A sac fly moments after a double? Give the sign, and make it happen. These little edges, just an 80% probability sprint away, are going to be tantalizing in the playoffs. Some team could conceivably break the 2008 Rays’ record of 24 steals in a postseason or the 2008 Rays’ and 1999 Braves’ shared record of 27 attempts.

Sure, some hulking contenders might continue to play it safe and simply swing for the fences, but baseball’s prevailing winds are blowing runners away from that safety, toward more adventure on the basepaths.