The defensive shift– repositioning infielders from their conventional locations in response to a particular batter’s hitting tendencies– may be the most significant development in baseball defense since pitchers started actually trying to miss bats with their pitches. The basic idea is that defenses can take advantage of certain hitters who are known to possess extreme tendencies in terms of batted ball direction by loading up their infield defense in line with that batter’s tendencies.

David Ortiz is a decent example of a batter with a definite tendency to hit the ball in a particular direction. Here is a spray chart showing where he hit every ball during the 2012-2014 seasons:

Ortiz is a top-tier power hitter, so it isn’t surprising that he’s peppered the entire field. Focusing on his ground balls, though, reveals a pretty strong tendency to hit grounders to the right side of the infield. Opposing teams noticed and began to counter Ortiz defensively by shifting against him.

Probably the most common way to arrange a defensive shift is to move the second baseman into shallow right field, move the shortstop to the first-base side of second base, and shade the third baseman heavily toward second base. Teams also employ less and more extreme variations of this basic shift. Because a fielder needs to remain close to first base, teams almost exclusively shift to overload the right side of the infield. This, in turn, means that teams almost always shift, if at all, against left-handed hitters, who, as a population, generally hit the ball to the right. Ortiz is a lefty, and his spray chart evidences the expected pattern.

No player faced a full defensive shift more than Ortiz in 2015, when opposing defenses shifted on more than sixty-three-percent of his plate appearances. The most effective antidote for the shift is a bunt to the exposed third-base side, but Ortiz, now at forty years old and at least 6’3″ and 230 pounds, has not been the bunting sort of late or, really, ever. He’s a big, left-handed power hitter in the last year of his career, and, as concerns the defensive shift, he’s just going to have to take his lumps.

A little further down that list of 2015’s most-shifted appears Victor Martinez in the #22 spot. Martinez spent much of 2015 injured, so he only made 485 plate appearances, seeing a full shift on roughly forty-three percent of them. Like Ortiz, Martinez is heavier, slow, and hits from the left side, and his 2012-2014 spray chart shows similar batted-ball tendencies to Ortiz’s:

One way in which Martinez is unlike Ortiz, though, is that, while both bat left-handed, Martinez also bats right-handed. The careful reader will note that the above spray chart only shows Martinez’s batted balls in plate appearances against right-handed pitchers, so limited so as to attempt to parse out Martinez’s plate appearances in which he hit as a lefty (batter handedness is not a control element on Brooks Baseball). Below are Martinez’s spray charts against left-handed pitchers and his combined chart for the same seasons:

As expected, Martinez displays the opposite directional tendency when hitting as a right-hander, and, by employing his switch-hitting approach as appropriate to leverage platoon advantages, spreads the ball to all fields when viewed as a total hitter. (There’s a reason he finished second in the 2014 MVP vote playing as a designated hitter.)

Due to health reasons, Martinez had a tough season last year; by wRC+, it was the worst offensive season (77 wRC+) of his career. On top of that, the shift really ate him up. When shifted against, he posted an unsightly 37 wRC+. Again, 2015 was a bad year for Victor.

As noted above, the bunt is one strategy for beating the shift. Trying to hit the ball to the opposite (i.e., left) field is another. Trying to hit the ball in the air over the shift is a third. For most batters, that’s it, and for most batters, none of that is working too well.

Martinez has a fourth option, though: he could hit right-handed against right-handed pitchers. Defenses rarely shift against right-handed hitters, and Martinez shows clear pull tendencies from the right side, making him a bad shift candidate when hitting from that side. In other words, if Martinez only hit right-handed, teams probably wouldn’t shift on him at all. How’s that for beating the shift?

Some argue that the shift’s advantage is less about fielding anticipated ground-ball patterns and more about trying to force hitters to do things– bunt, hit to the opposite field– they aren’t used to doing and aren’t good at. The shift, or the threat thereof, thus is more powerful than it may initially appear.

For any player, changing strategies is likely to have a cost. For Martinez, we should begin with the assumption that he is switch hitting in an optimal manner. After all, he has been an excellent hitter by doing things his way for fourteen seasons. The defensive shift is a new strategy, though, so it presents a valid reason for reassessing Martinez’s approach.

In order to justify a change in strategy, the net benefits of the proposed strategy obviously need to outweigh the net benefits of the incumbent strategy. While limiting Martinez to right-handed hitting should avoid entirely the shift’s direct costs, there are costs associated with Martinez hitting only from the right side, and they are more difficult to estimate. We know he hits lefties well from the right side (119 career wRC+). His 111 wRC+ hitting right-handed against right-handed pitching also is above-average, but he’s barely taken that approach (just nineteen of over 6600 career plate appearances), and he hasn’t done it at all since 2011, when he did it just three times; that 111 wRC+ number is almost meaningless.

We really don’t know much at all about how Martinez would perform if he started hitting right-handed pitching as a right-handed batter. It almost certainly would be worse than his overall career performance, as well as his performance as a right-handed batter against left-handed pitching, because almost every player hits worse against same-handed pitching, and because all changes at least have adjustment costs, maybe especially so late in careers.

The good news for Martinez is that it might not matter. Would a 37 wRC+ against the shift justify a drastic change in strategy? Almost certainly. What about a 112 wRC+ against the shift? For a career 122 wRC+ hitter, no way. Martinez posted 112 wRC+ against the shift in 2014 in almost exactly the same number of plate appearances in which he faced the shift (and registered that 37 wRC+) in 2015. In fact, Martinez wasn’t great as a left-handed hitter under any defensive circumstances in 2015, his injuries– chiefly, a bad left knee– making it nearly impossible for him to generate any power whatsoever from the left side. Yes, 2014 was a career year he’s unlikely to replicate in his later thirties, but (deep breath), assuming he stays healthy, there seems to be little reason for Martinez to deviate from his switch-hitting strategy. If the injury bug bites him again (he did suffer a “mild” left hamstring strain in spring training but started the regular season just fine, thank you very much), he may want to reconsider. With all systems go for now, though, we probably can leave the professional hitter to his work.