Chicago Cubs: In a game of inches, this is what to watch for this season

5. Heyward’s double stroke

Asked this winter by NBC Sports who will be the Cubs’ 2018 MVP, Jason Heyward answered “me.” Your guess whether this is just sports psychology positivity or his real belief. But with an opt-out clause this year and next, he has every incentive to rebound for one more bite at the free-agency apple.

I’m not foolish enough to bet on this, but the last time Heyward had a walk year (2015), he posted his best WAR (6.6). If you’re looking for a rebound indicator, watch that doubles rate. This was the main difference between his 2015 and 2017. Last year, he managed roughly the same homer, walk and K rate as 2015, but just 17 doubles versus 33 in 2015.

Interestingly, those who think he hits too many grounders and not enough line drives aren’t correct. Heyward’s line-drive rate is essentially unchanged since 2015, and his groundball rate dropped from 58 percent to 49 percent last year.

What has changed is his contact has weakened. This reflects fewer hard-hit one-hoppers going past (or off) infielders and fewer hard-hit line drives getting past outfielders to the wall.

Going Chili to get hot

To my eye, both are symptomatic of a swing exploding too near the center axis of his body. To create more force on contact, activation of hips and wrists should time together further out front. Homerun hitters do this in an extreme way, and contact double hitters more moderately.

Next: Happ-y times at leadoff

It’s too early to know if his winter work with hitting coach Chili Davis will correct any of this. For those who enjoy tea leaves, his doubles rate this spring is twice what it was last camp. However, his K rate also jumped from 17 percent to 25 percent. Does this indicate starting to apply a more aggressive doubles stroke that just needs more regular season reps? Or a small sample aberration?

Impossible to know until the games count. And by then, I hope you enjoy studying all these fun baseball nuances and any shared by readers below.