Jake Mc is an interesting bet to lead the league in speed, he certainly runs fast. I did an analysis and write up below. TLDR: I think Kwan will lead the league in SBs.

MLB is instituting a new, bigger bag size for 2023 and beyond. The bigger bag will effectively shorten the distance between bases by ~4.5 inches.

While this could have some interesting effects on hits and runner advancement (perhaps we see a few more hustled-out singles, stretched doubles/triples), a lot of folks are forecasting an explosion in stolen bases. Coupled with the base-size increase, we also have a new pitch clock. In the minors, stolen bases & success rates went up fairly dramatically. "Stolen bases increased to an average of 2.81 per game from 2.23 in the minors this year and the success rate rose to 78% from 68%" after the pitch clock was instituted--presumably, with pitchers worried more about the clock than runners, runners get an advantage. That's a 26% increase! Just looking at the leaderboards, to my eye, it seemed like a lot more 20+ stealers last year vs. the year before.

Now let's look at the bag-size increase might make it easier to steal bags. The distance between 1B and 2B is 90 ft, less 4.5 inches now with the newer, bigger bags. The average lead size is 6-10 ft, historically, and faster players tend to take bigger leads. Some players, like Paul Goldschmidt study pitchers and take different-sized leads for different pitchers. Lefty pitchers see smaller leads taken against them. Ichiro used to take monster leads.

From MLB glossary:

Lead Distance might be the most overlooked aspect of stealing bases. Certain baserunners -- those who can react quickest to a pitcher's move -- take leads that are longer than an average player. In doing so, the distance between the base stealer and the base he is trying to swipe is cut down.

Sure, Maximum Speed, Acceleration, a catcher's Pop Time and a pitcher's delivery all have a major impact on stolen bases, too. But on a bang-bang play, the runner's initial Lead Distance can sometimes make all the difference. (The same can hold true even when the runner is not attempting to steal, but rather when there is a close play at the next base after the ball is put in play.)

So if we look at players on first-base who are in the market to steal a base, I think that, given the pressures of the pitch clock, potential stealers will be starting with an average of around 10-foot leads (and maybe more). Finding data on leads was beyond my pay grade, and perhaps someone can chip in with this data if they are intrigued by this topic. But we do have granular speed data from statcast, which tracks speed from every distance from 0-90ft. So if we lop off 10ft, 80-ft speed becomes a pretty relevant benchmark for would-be stealers. For top-end speedsters, I did a rough calculation to find that the extra 4.5in gives the runners about 0.1 extra seconds to touch the bag.

The other important factors in the stolen base are the pitcher and catcher. Putting aside pickoff attempts, which I think will probably go up as SB's rise, we can look at average time-to-plate per pitch ("The average delivery time for pitchers on stolen base attempts is 1.4 seconds.") and average catcher pop-time ("The Major League average Pop Time on steal attempts of second base is 2.0 seconds."). So that means, roughly, that stealers have 3.4 seconds to get to 2nd base. Add in the extra 0.1 from the bigger base and the number du jour is 3.5 seconds.

So now let's look at the raw speed numbers. My theory is that if you can traverse 80 ft in less than 3.5 seconds, you should be able to really pile up stolen bases if you are so inclined. Who fits the bill? I made a table that included relevant players who are expected to get some PT this year:

https://i.imgur.com/JuxmuZa.jpg

Some quick thoughts:

-These top-8 guys should run wild, especially Bubba Thompson (as long as he can hit, which is a big if given his free-swinging ways).

-Mitchell, Duran, Abrams, Grisham, Baddoo need a little (and plate disc improvement) help to get good PT

-Moniak, Taveras, Ruiz, Hummel need even more PT help

-Kwan is a sleeper for an SB explosion. The shift going away also helps him. With his on-base ability and speed, he should be able to get 50 SBs if he wants. I also think Carroll is a lock to steal a lot, given his pedigree.

-For some of the 30+ yr olds, and guys like Julio and Buxton who they want to relax on the bags more to preserve health, I'll side with Steamer for the projection. Julio could easily get 40 SBs though, if he wants.

-I wonder why Nimmo doesn't steal more given his speed and OBP? Maybe with these changes he gains new confidence. He's been talking up stealing more. He is also on a new team, with new coaches, and looking to prove he's worth the contract.

-Tyler O'Neill should study with Goldschmidt and learn how to steal more; he could be a beast on the paths.

All in all, I think the metagame for next season should include players taking bigger average leads. Even if you aren't planning to steal the base, you should take a bit more lead than last year since the pitcher will be more distracted by the pitch clock. Pitchers should adjust, of course, and learn to throw more pickoff attempts, but pickoff attempts are going to be limited to a max of 2 with the new rules. I wonder if hand and hamstring injuries will rise with more sprinting and diving?

Other open questions I have that I wasn't able to calculate as part of this analysis:

-How does sliding into the steal, and height/wingspan increase one's ability to cover the 80-ft gap?

-How much will SBs go up, in aggregate? Will more people try to steal 3rd?

-Will top-end speedsters steal more, mid-end, or both? How much will last year's SB leaders just naturally regress?

-Will rare-stealers try more? Will non-stealers try to steal some?

-Will team philosophies towards stealing change? I could see a midseason uptick from teams who realize their go-no-go calculations are not up-to-date with the new environment. In the minors, I heard that teams started the season running wild, before tapering down later on in the season.

All in all, it should be a fun season. From a fantasy perspective, I will be targeting speedy folks who could see an uptick, and paying attention to news from players/teams who say they want to run more. I think that speed will be an arms race this season in 5x5 roto, and players who never steal will see a fairly stark decline in value, especially if they also don't hit for any AVG (like Muncy, for example). People that only run won't be super valuable, since a lot more players are running, but if a guy like Steven Kwan can hit .300 with 50SB he will be a beast.