While I wrote about the possibility of extending Carlos Martinez and Michael Wacha over the off-season, the Cardinals didn't end up getting a deal done with either young pitcher. They did however, reach a long term deal with Kolten Wong, guaranteeing him salaries for his remaining four years of control, plus what would have been his first free agent eligible year. The Cardinals also retain an option for a second free agent year, which would be 2021. The total guarantee is for $25.5M over five years, with the option possibly pushing it to $37M. So it's not a hugely significant guarantee, but not chump change either. I voiced my support for the extension when it occurred, citing Wong's high floor and a lack of certainty in the Cardinals' second-base prospects as good reasons to gain an extra two years of control over Wong.

Things however, haven't exactly started off great for Kolten. He's one of six Cardinals with a qualified amount of plate appearances, and he's so far been by far the worst hitter, with a 41 wRC+ and Randal Grichuk's 96 wRC+ in second to last. Expand that to 30 PA and he's still in last, but at least has closer company with Matt Adam's 64 wRC+ included. Those three are actually the only below average Cardinals hitters with over 30 PA, with the eight others all hitting better than average. Let's look at Kolten's line:

Nearly all of Kolten's struggles can be pinned to one thing: zero extra base hits. You've probably already logically deduced that Wong is tied for last for last among qualified hitters with that ISO mark, but it might depress you to know that at this point he's only tied with one other qualified hitter, Chase Headley. Without looking at the walk rate, you might have assumed his plate approach, which has often been poor, was contributing to this. But it's not:

I used Correct% in my last article, that's a stat I calculated by taking the percentage of total pitches that were in the zone and swung at plus the amount of pitches out of the zone that were taken. The formula (after adjusting the percentages to fractions):

Correct% = (Zone% x Z-Swing%) + ((1 - Zone%) x (1 - O-Swing%))

The purpose of that stat is to show strike zone management, by showing how well the player does at swinging at pitches in the zone and laying off pitches out of the zone. Wong has laid off way more pitches out of the zone than he did in 2014 or 2015, though he loses some of that back with less swings in the zone as well. Overall, Wong is guessing right 3% more often than he did last year, which isn't nothing. It's certainly not the thing holding him back, considering he was a much better hitter (though still below average) in 2014 and 2015 despite worse plate discipline stats.

Going into the season one might have thought that if Wong made just slight improvements in plate discipline, it could be enough to push him up to an average hitter or better. But this affect has been completely overwhelmed by some very bad contact quality:

Yeesh, that is rough. his GB% is 26th highest out of 195 qualified hitters. Hustle doubles are pretty much the only extra base hits that occur on the ground, and they have to be pretty perfectly placed to happen. That is definitely a huge reason for Wong's lack of extra base hits. You can also cite the complete lack of hard hit balls. Wong's Hard% (...) is the third lowest in the league among those 195 qualified hitters. That's backed up by the more granular data: Ranked by average Exit Velocity, Baseball Savant has Wong at 185th out of 203 hitters with more than 30 tracked batted balls and BaseballHeatMaps has Wong's average fly ball distance at 233rd out 236.

Now, I'm actually writing this on Sunday. Wong's not in the lineup for the Padres' finale but will probably at least get a pinch hit appearance at some point, and I won't be able to update these stats after Fangraphs updates it's numbers for Monday's games early Tuesday morning, so Wong may, by the time you read this, added five or six more PA to his 2016 resume. But it shouldn't change the conclusion: Wong has so far, fared measurably better at controlling the zone, but been absolutely miserable at hitting the ball with any sort of authority.

To me this prognosis is very good news, as it seems less likely to continue as the season progresses. Wong's high leg kick has always lead scouts to note that he could struggle with timing against Major League pitching. With over 1000 PA at the MLB level before this year as a nearly average hitter even with a below average BABIP, we know Wong's high leg kick shouldn't stop him from being able to hold his own at the highest level of play. However, it does make sense that at times, particularly at the start the year, he might not be able to get his timing down and then struggle as a result.

When hitting against MLB pitchers, who nearly all throw at least 90 now and frequently throw in the mid-90's, just a few milli-seconds can make all the difference. Timing is crucial at this level, and it seems reasonable to believe that Kolten simply hasn't found his yet. With the plate discipline numbers, one can actually even be optimistic right now about Wong, as once he does find his timing, he might very well post better numbers than we've seen over a full season.

The more pessimistic option is that Wong's contact quality is due to his change in approach. In trying to improve his plate discipline, perhaps he's waiting several milli-seconds too long, and he's rushing his bat through the zone or changing mechanics or perhaps late going through the zone. At this stage though, it's not something to worry about. Wong's two prior full seasons offer evidence that he can produce around average quality contact at the major league level, and that didn't just disappear over the off-season.

Somethings gone awry, but that something should be fixable.It's certainly something someone much better at scouting than me should take a look at. In the meantime I think Jedd Gyorko and Ruben Tejada (Ruben by moving Diaz over to second) may cut into some of Wong's playing time, but he's still going to get reps to get out of this funk he's in. Look for Kolten to bounce back, and if the plate discipline progress is real, it may even be a new and slightly improved Kolten Wong.