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MLB and the Shift: Defense in the Modern Age

MLB and the Shift: Defense in the Modern Age

MLB and the Shift: Defense in the Modern Age

All told, Bryce Harper had a fine first season in the red pinstripes of the Philadelphia Phillies. Though the team fell far short of the goals it set for itself after inking the erstwhile Nationals star to a 13-year deal worth $330 million, Harper himself had a .372 on-base percentage and cracked 35 home runs.

Only one thing was missing: The former NL MVP, who came into the season with a .279 career batting average, hit just .260 and struck out a career-high 178 times. Harper faced shifted defenses 60 percent of the time, easily the highest rate of his career, and it psyched him out. In trying to hit around the shift, Harper got himself into bad habits and an unhealthy approach. Since the start of 2018, Harper has a near-elite .387 weighted on-base average (wOBA) when not facing a shift but a more modest .354 when shifts are on. That’s bad news, and if he wants to regain his superstar status, he’ll need to correct it because he’s only likely to see more aggressive opponent positioning in 2020.

In one sense, the majors saw a steep increase in the frequency with which teams deployed defensive shifts in 2019. In fact, a league that had previously shifted in 14.4 percent of plate appearances, from 2016 through 2018, suddenly shifted 25.6 percent of the time. The league went absolutely gaga for defensive shifts.

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In another sense, though, the league had no shifts in 2019. In the majors, and now on an increasing number of fields throughout the minor leagues, independent pro ball, collegiate competitions and even high schools, conventional perceptions of defensive positions and where players ought to be stationed are breaking down. There are no shifts anymore because what used to be called a shift now goes by a simpler name: defense.

One of the pioneers of shifting at the big-league level, at least in its modern incarnation, is new Angels manager Joe Maddon. However, Maddon’s Chicago Cubs shifted less often in 2019 than any other team in the majors, and they only narrowly avoided the same distinction in each of the three previous seasons. Maddon elected to do other things to maximize his team’s chances of converting batted balls into outs — things like moving defensive whiz Javier Baez around the infield, swapping first baseman Anthony Rizzo to second base when the opponent was likely to lay down a would-be sacrifice bunt and asking superstar slugger Kris Bryant to split time between third base and right field. Maddon boiled his philosophy down to a simple edict: “Put the best defenders where the ball is most likely to go.”

That’s the approach being adopted by the whole league, but rather than just get their best glove men in position to field a high percentage of batted balls, teams are choosing to get the most possible fielders into parts of the field where a given batter is likely to hit the ball. The concept undergirds all modern defensive decisions at the team level, and it’s turning the traditional notions of standard and radical alignments on their heads. The relative difficulty of positions has changed. The number of players asked to play multiple positions (and rewarded for doing so with aplomb) has risen. And the difference between a shifted and a shaded defense has become so arbitrary, so thin and so frequently redrawn as to be completely useless.

With the explosion of new information available to teams in the modern age, there are enormous opportunities to exploit specific matchups and tendencies, and teams are getting increasingly aggressive in doing so. In 2019, 65 batters saw shifted defenses in at least half their plate appearances — as many as in 2017 and 2018 combined. Briefly, in early 2019, four-man outfields even became a fad, pushing the limits of the sensible ways to cover fair territory with seven defenders. Batters such as Joey Gallo and Harper stepped to the plate, only to see half the infield open but the outfield dotted with a bizarre collection of defenders. (Those strategies mostly failed. The outfield, it seems, is too big and complicated to be solved by shifting.)

As this strategy proliferates, there are numerous unintended and far-reaching consequences. Batters have less incentive than ever to put the ball on the ground, where they’re likely to hit right into the teeth of a shift, so more batted balls than ever are hit in the air, where they might carry over the shift and land in the seats. The league’s average launch angle is up, and the global ground-ball rate is down, for each of the last five seasons (see below).

Percentage of Plate Appearances in Which MLB Teams Employed Defensive Shifts, 2016-19


v. RHH

v. LHH


















Average Launch Angle and Ground Ball Rate,
2015-19, MLB


Avg. Launch Angle

GB %
















Any swing engineered to create loft, however, necessarily risks a swing and a miss. Pitchers’ adjustments, including throwing more of the pitches that generate the highest rates of whiffs on swings, and the changing composition of the baseball also affect the typical batter’s calculus at the plate, but the shift is one factor clearly driving more hitters to trade contact for the potential power associated with lifting the ball (below).

Contact Rate on Swings, MLB, 2015-19


Contact %











The shift, then, is steering hitters into a more all-or-nothing mode, and thus creating a more homer-centric offensive game. In an infinite regression loop, that change also leads to a change in the way teams select infielders. If the league is seeing more strikeouts, more walks, and more fly balls when the ball is put into play, infield defense necessarily becomes less important, and that allows teams to slide bat-first players into positions they could not have played on a regular basis even a half-decade ago. With those sluggers hammering away at a ball that has flown out of the park at record rates in two of the last three seasons, there’s little reason for them to change their own strategies and lay down bunts or slap hits the opposite way, which could otherwise force shift rates to decrease.

The Reds signed veteran third baseman Mike Moustakas to a four-year deal over the winter, but they intend to play Moustakas at second base, while incumbent slugger Eugenio Suarez remains at the hot corner. A few years ago, such a move would have been unthinkable, but it came as little surprise. Moustakas played some second base for the Brewers in 2019, as they deployed the shift 34.1 percent of the time. The Reds, who hired David Bell as their manager prior to 2019 with an eye toward big advancements in the implementation of advanced information, shifted 27.0 percent of the time in 2019, up from a paltry 9.5 percent in 2018. Moustakas will spend much of his time heavily shaded in whichever direction the team might believe the ball will be hit, and that will help make up for his deficiencies in range and quickness. He’s a fly-ball hitter who hit 35 home runs in 2019, but Moustakas is now an acceptable second baseman.

In turn, Moustakas’ lack of hard-to-field ground balls allows opponents to shift aggressively, and they can then hide their own questionably qualified keystone men. The Brewers replaced Moustakas, in part, by trading for second baseman Luis Urias, whom they intend to move back to shortstop. Milwaukee’s second baseman, sophomore Keston Hiura, hit .303/.368/.570 in his rookie campaign, but he isn’t the kind of quick, sure-handed player teams used to prize at that position. Diminutive but powerful, Hiura is the type of player teams used to move to left field, but he figures to stick at second base in Milwaukee’s shift-happy scheme.

The same trick can now work on the left side of the infield, an especially new development. The rate at which right-handed batters encounter shifted infields is rising much more rapidly, proportionally speaking, than for left-handed batters. In 2018, Edwin Encarnacion became the first righthander on record to see shifts at least half the time. In 2019, seven players cleared that bar, and Phillies slugger Rhys Hoskins saw shifts 492 times, accounting for over 70 percent of his plate appearances.

The Dodgers and Twins shifted 42.2 and 34.9 percent of the time against right-handed batters, respectively, and that reflected not only their best estimates of where opposing hitters would hit the ball, but also the ways they each wanted to set their defensive lineups.

At 34, Justin Turner is beginning to show the effects of age and a pair of injury-shortened seasons. Formerly an above-average third baseman, Turner slipped to the brink of being unplayable at the hot corner in 2019, but because the Dodgers crowd the left side of the infield against righties, their veteran third baseman’s limited range didn’t hurt as much as it might have. The same shifts also helped hide the lack of great range from Corey Seager, a young and athletic shortstop, but an oversized one. The Twins, similarly, got away with Jorge Polanco as their regular shortstop, despite Polanco’s slow first step and erratic arm. One underestimated impact of shifting can be that players with weak or error-prone throwing arms find themselves having to make fewer hurried, running or off-balance throws.

With each passing season, individual defensive range matters less. With each passing season, teams select players more for power, and less for any defensive skills. With each passing season, the hitters who do get opportunities face stronger incentives to hit fly balls, and speed becomes less valuable. The average player is more athletic each year, as the game continues to advance, but less and less of that athleticism takes the form of speed. Between slower hitters and more efficient positioning, the league is hitting worse on ground balls than it has in years (below).

Batting Average on Ground Balls, MLB, 2014-19















That doesn’t mean that shifts have had an unmitigated negative impact on offense, or that they work perfectly. The aforementioned four-man outfield shifting didn’t work. When left-handed batters pulled long line drives and fly balls into shifts that featured a second baseman playing especially deep, they fell in much more often than would be expected. On balls in the air, especially, an effect called diffusion of responsibility begins to counteract the value of having several people in the area: The presence of others who could make a play reduces each fielder’s tendency to take action and make the play himself.

Unique alignments also have an impact on the most important individual actors in a team’s defense: pitchers. Research by former Baseball Prospectus author Russell Carleton has demonstrated that, on average, pitchers throw fewer strikes when the fielders behind them are aligned in a non-traditional way. In some cases, he even found that the net effect of the shift was zeroed out — that every hit that was stolen by strategic positioning was canceled out by a walk issued by a flustered hurler. Carleton joined the Mets front office as an analyst in 2019, and the team slid from 21st to 28th in shift rate.

Teams aren’t merely steeped in technology and data-driven decision-making, however. Increasingly, they engage in nuanced hiring and communication practices. Rather than accept that shifting creates certain problems and scale back the practice, clubs have found ways to provide valuable information to their players in digestible forms and mitigate some of those problems. Pitchers have been retrained to approach plate appearances in front of shifted defenses the same way they would otherwise — to consider shifts as ordinary defensive strategies, rather than some intimidating extravagance. As that attitude takes root, individualized alignments become more and more normalized.

Unexplored frontiers of shifting remain, and plenty of teams still could ratchet up their creative positioning. Whereas five teams shifted against righties over 25 percent of the time in 2019, 14 clubs shifted against them less than 10 percent of the time. The latter 14 teams are much more likely to make changes in 2020 than are the former five. Of the 10 teams that shifted least overall, six have new managers, which makes them likely to move back into the mainstream. More important, of the eight teams that shifted most, six made the playoffs. As teams master the human element and connect efficient information management with savvy personnel management, defensive alignments that would once have been extreme and uncomfortable have become so familiar that they can go unremarked-upon, and players can execute them without complication. The future of defense is a team-focused, positionless and data-driven endeavor.

For fans, there’s a cost involved. The style of play engendered by the various factors shaping the modern game can be ugly and stagnant. The game is losing speedy contact hitters and gaining sluggers who are technically more valuable but often less entertaining. The defensive highlight reels put together by some of the great infielders of yesteryear are impossible for their modern counterparts to duplicate, not because Andrelton Simmons is an inferior fielder to Ozzie Smith (he isn’t), but because Smith averaged about five more fielding chances per week than does Simmons, and because shifted defensive alignments require fewer dazzling plays from each individual.

Until something changes the current equation, however, teams will continue to trade the small pleasures and aesthetic advantages of old-school baseball for the harmony and tidiness of technocratic planning.

— Written by Matt Trueblood (@MATrueblood) for Athlon's 2020 MLB Preview. At 224 pages, it's the largest on the newsstand and the most complete preview available today. Click here to get your copy.