January 2023

As spring training approaches, several rules changes are going to take effect for the 2023 MLB season. One of the bigger changes is banning of the Shift so that teams can no longer have three infielders play on the same side of second base or act as a 4th outfielder. The general idea is that banning the Shift will increase offense across the league.

Through a detailed investigation, I have found that to indeed be the case but not quite in the way people expect:

• The Shift frequency has been increasing since 2017 with close to 50% of the plate appearances for left hand hitters and 20% of those for RHH having some form of positioning in the infield or outfield that will be banned in 2023.
• The banned shifts have not been reducing offense during that time period. In fact, for 2017 through 2021, the mean weighted on base average, or wOBA, for the league has been higher for plate appearances with the banned shifts versus those without (!)
• The surprising result is due to the ~25% increase in homeruns hit against the Shift, with homeruns counting for 2 runs on average versus less than 1 run on average for balls hit into play where the defense can get involved.
• Banning the Shift therefore appears to have more to do with changing the outcomes of Balls in Play, especially for left-handed hitters and increasing the entertainment value for the fans.

In addition, I discovered the following by analysing the 2022 data from a player perspective:

• There are several players that did poorly against the shift last year who have thus projected upside for the 2023 season. Players to watch for bouncebacks from banning the Shift include recently signed FAs Carlos Santana and Mitch Haniger, unsigned Robbie Grossman, recently traded underperformers Dominic Smith and Abraham Toro, and young disappointing players Jared Kelenic and Josh Naylor
• Several players did poorly against regular defense instead of the banned shift including well-traveled Lewin Diaz, on-the-block Max Kepler and maybe-not the LF for the Yankees, Aaron Hicks. Other players to watch in this space are playoff hero Kyle Schwarber, disappointing Rockie superstar Kris Bryant and the recently DFA’d utilty man Kyle Garlick
• For the Jays, there isn’t much expected change except a possible positive change for new CF Kevin Kiermaier and a possible regression for new DH Brandon Belt.

Like everything though, past performance is no guarantee of future value. Player injuries, coaching, training and luck all have a strong effect too. Nevertheless, it will be fun to watch what happens to the players discussed above and the league in general in the upcoming season.