Baseball is not a set of rules. Never has been. Baseball is the way players and teams pursue wins inside (and sometimes decidedly outside) the lines drawn by the book and on the field. So when the 2023 MLB season rolls around, there will be some exceedingly interesting baseball to watch.

The new rules announced earlier this month will force players and teams to adjust in several aspects of the game. The pitch clock and its related limitations on pickoffs introduces a totally new element to the major-league game, but we’re here to talk about the shift — or the shift in how teams will shift — and the ways it could visually and strategically alter the game.

MLB’s new rule seeks to walk back an age-old strategy that has evolved into a near ubiquitous and perhaps too-efficient hit eraser. Starting in 2023, the defending team must have two infielders on each side of second base, all of them in front of the outfield grass, when each pitch is delivered.

That will effectively prohibit the three most eye-catching — and announcer-baiting — forms of the infield shift: The one where there are three fielders loaded up on one side of second base, the one where the second baseman is essentially playing shallow right field, and the one where there are just four outfielders.

In place of those alignments, new (or newly prevalent) arrangements and tactics will emerge. The same minds that have been printing out those little cards players have in their hats will be devising ways snuff out as many hits as possible within the added limitations.

What will that look like when it hits the field next April? Well, we can’t totally know yet, but we have a few guesses.

Middle infielders living on the edges

The most predictable outcome of the new boundaries will be infielders lining up as close as they can to the forbidden territory. Mostly, that will mean shortstops getting as close to the imaginary line running through second base as they possibly can when left-handed hitters are batting.

Lefties get shifted far more often, and far more effectively, than right-handed batters. Improving defensive tactics have driven left-handed hitters’ batting average on balls in play (BABIP) down to .282 this season, a level not seen since 1972 — a defensive slog that led to the creation of the designated hitter. Generally, BABIP has been understood to hover around .300, but as defenses have learned to customize themselves for each hitter, that number has taken a dive. Overall league BABIP was between .295 and .300 every season between 2004 and 2019. But it dipped to .292 in 2020 and 2021, and is sitting at .290 in 2022.

Good defense isn’t a bad thing, of course. No one wants to turn games into batting practice. The idea is to make good defensive results require … actual good defense, the kind with athleticism and visual stimuli involved.

Teams aren’t going to take MLB’s conceptual goal as a marching order and place all their fielders in the traditional Little League diagram of the positions, though. A whole bunch of balls that “should be hits” by the old school logic of the game will still be outs. Chief among them: The line drive up the middle. Keep in mind the rule only states that infielders have to be on the dirt, on the prescribed side of second when the pitch is released. While the second basemen will have to be on the dirt next year, the shortstops who often take away those knocks when they shy to the left of second base are in perfectly legal position, even by 2023 standards.

(Don't be surprised if that gap is eventually closed, too. MLB has tested an even stricter version of the shift limitation in the minors, dubbed the pie slice rule, that would open up the middle of the field by prohibiting infielders from standing within a certain wedge of the field around second base.)

Depending on how important teams think these margins are, we may even creep toward a situation where middle infielders are taking “secondary leads” a la base stealers. With each pitch against a left-handed pull hitter, maybe the shortstop begins closer to his traditional hole, but is walking toward the right side, bursting into a full run when the ball leaves his pitcher’s hand.

It could be very fun!

There are complications to the timing of that, especially with men on base, but it’s not hard to envision the potential.

Look at this looping line drive off the bat of the Rangers’ Nathaniel Lowe. The A’s are playing defense, and the alignment is totally legal by the incoming 2023 standards.

The outcome, though, is very 2022. A shortstop grabs what looks like a hit on the other side of second base.

Left fielder? More like intermediary right fielder

The hitters who inspire the most extreme shifts are burly left-handed power hitters. Their batted ball profiles involve a bunch of deep, high fly balls, and virtually everything on the ground is pulled.

A lot of the moments that drive down batting averages, and that sparked the rule change, are designed to stifle these hitters. When they work, they barely involve any movement at all. There’s just a guy standing where the ball lands. Like when Phillies bopper Kyle Schwarber hits a ball right at Braves third baseman Austin Riley … who was stationed in shallow right field.

At their most extreme, they are pretty much a snapshot of everything MLB banned for next year.

That’s how the Tigers set up against Yankees first baseman Anthony Rizzo in June. Four deep outfielders, one second baseman playing in the outfield, a first baseman and a third baseman whose job is to scare Rizzo off the idea of a bunt double. In this case, Rizzo hit it right to the second baseman playing shallow right field.

Perhaps the biggest question going into the new world of limited shifts is how much risk teams are willing to take to cover short right field against the likes of Rizzo, Schwarber, Juan Soto, Matt Olson and others.

While the second and third basemen are now barred from manning that advantageous spot, the outfielders are not. It’s possible that against some hitters, teams may bring their left fielder in to play that role. MLB.com’s Mike Petriello helpfully diagrammed what that could look like with the 2023 rules in place.

In essence, it creates a greater risk/reward dynamic if they want to take away that basic line drive hit. The rule changes are in place because the “go the other way” adjustment never came for hitters. If teams think it never will, then vacating the left field line and risking a triple might make sense. Or, it could create a different type of pre-pitch motion, like the shortstop running toward right field. Maybe a third baseman starts in his usual position to guard against the bunt, but then sprints backward to make sure a can of corn can’t land in left.

The players in the lineup will have to change

Whether teams go with motion-heavy innovations to replicate the shift or adhere to more normal versions of infield defense, the demands upon infielders are changing. A trend toward pushing slower-footed sluggers toward more demanding defensive positions, then covering for them with shifts, will be reversed.

Max Muncy and Mike Moustakas, the poster boys for that idea, will go down as second baseman of a very specific era. Going forward, they will be designated hitters or first basemen.

Beyond the players who will be subbed in and out of major-league roles, there could be considerations of more specific fielding skills. If you’re thinking about risking a dramatic outfield shift, maybe you’re more likely to do so if you have a shortstop or third baseman who is particularly adept at fielding fly balls behind them.

Those sorts of directional breakdowns are already publicly available through Statcast, so you can be sure teams have even more advanced metrics to gauge their players’ abilities. The public data, for instance, points to Trea Turner — the star Dodgers shortstop approaching free agency — as an infielder who does well turning and running to grab a fly ball over his shoulder.

It’s not going to move the needle nearly as much as his MVP contender-caliber bat, but it could be an important bit of information for a team planning for the brave new world of defense.