And we're off! The start of the 2023 season brings with it the most changes of any season since 1969 -- when Major League Baseball split into divisions for the first time, lowered the mound and redefined the strike zone while adding four expansion teams.

The new rules promise a faster-paced game and, hopefully, a return to a style of play with more stolen bases, more base hits and more opportunities for the best fielders to demonstrate their excellence.

The pitch timer is in. (Pitchers will have 15 seconds to deliver a pitch with nobody on base and 20 seconds with runners on -- and the batter must be ready to hit with eight seconds on the clock.) The shift is out. (There must be two fielders on each side of second base and infielders must play on the dirt.) The bases are a little bigger, and pitchers are limited to two disengagements -- pickoff throws or stepping off the rubber -- per plate appearance.

There's a chance very little might change, but let's dig into some areas of the game and consider which players and teams might be most affected by the new rules.


The shift

Left-handed hitters, especially pull hitters who hit grounders

  • Key players to watch: Corey Seager, Kyle Schwarber, Shohei Ohtani, Yordan Alvarez, Max Muncy

Let's get this out of the way: By left-handed pull hitters, we really mean all left-handed hitters. And don't "Tony Gwynn" me here. You know who pulled most of his ground balls? Mr. Tony Gwynn. He had 3,203 ground ball outs in his career; 64% of them went to the first baseman or second baseman. If we include grounders back to the pitcher, it was 73%.

All hitters, when they hit the ball on the ground, are more likely to pull it. But some hitters will be helped more than others.

Over the past three seasons, the lefty hitters with the most ground ball outs were Alex Verdugo, Raimel Tapia, J.P. Crawford, Nicky Lopez and Adam Frazier. We're not talking about those hitters, although they should get a few more hits. We need to look at the lefty hitters who hit the ball hard and whom extreme shifts are most often deployed against. The most shifted batters in 2022 on a percentage basis, according to Sports Info Solutions (SIS) data: Seager, Schwarber, Ohtani, Seth Brown, Rowdy Tellez, Cody Bellinger, Alvarez, Kyle Tucker, Muncy and Mike Yastrzemski. All left-handed hitters with power.

Statcast classifies a hard-hit ball as 95 mph or higher. The list of lefty hitters with the most outs in 2022 on grounders of 95-plus mph: Christian Yelich (72), Rafael Devers (59), Tellez (58), Alvarez (58), Matt Olson (55), Seager (54), Brandon Nimmo (49), Verdugo (48), Cedric Mullins (48), Nathaniel Lowe (47) and Juan Soto (46). Those hitters are all going to love seeing the shortstop on the left side of second base.

Those totals also don't include the short line drives that were caught, particularly those when the second baseman was playing in shallow right field. Because infielders have to start on the dirt, some of those liners are also more likely to go for hits.

Seager is the prime example here. He went 18-for-161 (.112) on grounders and short line drives hit between first and second base in 2022, and SIS estimated that he lost 29 hits to the shift., using Statcast data, put it at a more conservative 20 hits when applying 2023 positioning rules. Add 20 hits to Seager's 2022 ledger and his batting average goes from .245 to .278. His OPS climbs from .778 to .836. His .423/.474/.673 spring training line already shows a difference.