Why is Ian Kinsler struggling offensively?

On May 17, while the Detroit Tigers were on their way to a 2-1 loss in St. Louis, Ian Kinsler tallied two hits and a walk. One hit was of the infield variety, while the other was a knock to right center. At this point, Kinsler was hitting .318/.386/.411, a solid on-base presence at the top of the order.

A month and a half later, Kinsler's batting line has sagged all the way to .261/.334/.347, giving him a 92 wRC+ on the year. His on-base percentage is actually quite a bit higher than it was in 2014, but his batting average and isolated power have tanked. His power is especially abysmal; Kinsler ranks 141st out of 161 qualified batters in isolated power (ISO). No doubt, since his slump started, Kinsler is weighing down the top of the lineup.

What is the cause of the second baseman's struggle? It seems he is changing his approach. Before the season, he was working on hitting the ball to right field more. At just 40 percent, Kinsler has a lower percentage of balls hit to left than at any other point in his career. On the flip side, 26.1 percent of his contact went to the right side, a career high. It's very likely this is why Kinsler's power numbers have declined: his career ISO to the pull side is .328, while his ISO to the the opposite side is .069.

In 2015, though, Kinsler has seen a role reversal. The table shows how his pull percentage corresponds to power and overall hitting.

As we can see, he has regressed over the last few months from spraying the ball everywhere to pulling the ball again. Given his career averages, we would expect to see his batting average and on-base percentage to drop slightly as he became pull-happy in June, with an offsetting rise in power. Instead, the bottom has fallen out during the past month. He's hitting a lot more fly balls, at 45.8 percent in June versus 37.0 percent in April, so what gives? Why isn't Kinsler starting to hit homers and doubles again?

It's possible this extended slump is nothing more than a blip on the radar and we'll see his ISO double in the month of July, or perhaps there is something truly wrong. Kinsler is now 33, and his power-hitting skills are going to decline at some point. As the Tigers have seen in recent years, no player is immune to the effects of time. Kinsler's efforts to become a better opposite field hitter may be what he sees as a tool for survival as he enters the latter stages of his career.

The slump of Ian Kinsler will be something to watch as we approach the midway point of the season. How he breaks out of the skid remains a mystery. The pull-happy power hitter of 2014 or the on-base machine we saw early in this season would both be quite valuable to the Tigers.