Hoornstra: Baseball’s new stolen-base calculus is a great leap forward

The concept of stealing a base doesn’t explain everything about baseball in 2023, but it helps.

Poke and prod and ask a player enough questions about base stealing strategy, and eventually, he’ll give you some version of the same response: “it’s all an equation.” The best players and coaches in the world can reduce the stolen base – the ultimate combination of brains and brawn, of speed and strategy – to a math problem.

How boring.

A new set of rules for the 2023 season was designed to fix that. Major League Baseball’s dirty little secret is that, to this point in the new season, nothing has changed: When the math tells a player it’s worth attempting to steal a base, he will find a spot to steal a base. The math is just a little less noticeable when every team is burgling like Robin Hood at a yacht party.

Why? Because the new rules have completely changed the calculus – and the strategy – of stealing bases. It’s challenging some of the most basic assumptions that once held true from Little League to the pros. The new stolen base landscape is a Great Leap Forward for MLB, literally and figuratively.

Here are just a few early examples of what’s different.

1. It’s still harder to steal against left-handed pitchers than right-handers, but …

… The gap is narrowing. Via Baseball Reference, here are the numbers through Tuesday:

SB% vs. RHP

2022: 76.5

2023: 81.6

SB% vs. LHP

2022: 71.7

2023: 78.3

Pitchers can only throw over to first base twice before incurring a balk now, and this is where you would correctly predict this new rule to enter into play. If a baserunner can draw two throws over to first base, it doesn’t matter if the left-hander on the mound has the best pickoff move in the world. The runner has the advantage. And the numbers bear that out.

2. Steal third – please!

Stealing third base isn’t as easy as converting an extra point in football, but it’s getting close:

Runner on 2nd, SB%

2022: 167 of 218 = 76.6%

2023: 32 of 34 = 94.1%

Runners on 1st and 2nd, SB%

2022: 210 of 253 = 83.0%

2023: 36 of 37 = 97.3%

In 2022, a stolen base was attempted on 1.8% of all chances with a runner on second and third base empty. Through Tuesday, there’s been a stolen base attempt on 2.3% of all chances with a runner on second and third base empty. The data suggests that teams aren’t fully taking advantage of their new gift.

There are mitigating factors, however. A base hit to the outfield usually scores a runner from second or third base, so the upside of stealing third is limited to certain situations – namely, when a sacrifice fly can score a run with zero or one outs.

Nothing angers a coach more than running into an inning-ending out at third base. That much hasn’t changed: through Tuesday, there were only 10 attempted steals of third base with a runner on second and two outs. Naturally, all 10 were successful.

3. Stealing bases doesn’t make bad teams good. But they’ll make a difference in close games.

Last season, the Arizona Diamondbacks were credited with more runs scored above average through baserunning (mostly through steals) than any team, with 17. The Washington Nationals, at minus-13 runs, were baseball’s worst baserunning team. And it looks like the disparity between the best and worst base-stealing teams is growing.

Two teams (the Kansas City Royals and Boston Red Sox) had yet to be caught stealing through Tuesday. Two other teams (the Dodgers and Minnesota Twins) were still less than 50% successful on their stolen base attempts. Outliers usually regress to the mean, but the early results suggest teams are still feeling out their risk/reward assessment.

Despite employing one of the game’s fastest players, the Twins had only attempted three steals through their first 17 games. At the risk of boring you with the math, here’s why: a team gains less than two-tenths of an expected run when they steal second, less than three-tenths of an expected run when they steal third base, and less than half a run when they steal second and third. If you’re Byron Buxton – fast as lightning but brittle as glass – the injury risk is too high, even when the stolen base is practically a freebie.

Still, those marginal advantages add up in close games. In addition to their 3 for 7 success rate on stolen base attempts, the Dodgers are a mere 4 for 28 throwing out attempted base stealers. Manager Dave Roberts estimated that disparity could be costing his team “two to three” wins.

“And that’s just the first thought – giving the value of an extra base or 20 extra bases, giving away four extra outs,” Roberts said.

4. It’s taking a psychological toll on catchers

New York Mets manager Buck Showalter was featured in one of MLB’s preseason ads with portly slugger Daniel Vogelbach, who wanted to take advantage of the new stolen base environment.

Now, all joking aside, Showalter thinks the rules encouraging stolen bases are “the biggest change in the game.”

Two observations stood out to him.

One, “it’s bringing people into play that don’t normally steal because they can get a running lead,” Showalter said. “Unless a pitcher’s willing to get on the mound with 13 seconds left (on the pitch clock) and know what pitch he’s going to throw where he can hold the ball, these guys are going to continue to get running leads. It’s going to get hard for catchers to throw them out.”

That led to Showalter’s second, more distressing, observation: “one of the jobs you have now is keeping catchers from getting down on themselves.”

Philadelphia Phillies catcher J.T. Realmuto threw out more attempted base stealers than any catcher in 2022 – 30 of 68 would-be thieves, a whopping 44% success rate. Through his first 15 games of 2023, Realmuto is throwing out a mere 29% of base stealers.

“Everybody’s got the math on how many times people throw over. What you’re going to see more and more is people throwing over three times. When they’re stealing second at a 95% rate, you might as well take another pop at ’em, especially when they’re cheating.

“That commercial we did with Vogey? It’s coming.”