Platooning Kolten Wong and Jedd Gyorko

Last week, the Cardinals announced that Kolten Wong would be part of a platoon with Jedd Gyorko. As Mark Saxon noted, Wong did not react well to the news (although he later clarified that he would prefer to stay in St. Louis). Kolten and the Redbirds agreed to a five-year, $25.5-million contract last spring, but what might have served as a confidence booster for the young second baseman resulted in a slash line of .240/.327/.355 over 121 games.

The reason for this platoon is Gyorko’s bat. He did lead the Cardinals with 30 home runs in 2016, a number that had him tied for 11th in the National League. But is Gyorko that much better offensively to offset Wong’s defensive attributes?

Let’s look at this from two different perspectives: in the field and at the plate.

In the Field

Using data from 2015 and 2016, Wong and Gyorko played over 1000 innings at second base — a large enough sample size to use in an analysis. Examining the Ultimate Zone Rating per 150 games (UZR/150), we see that Kolten and Jedd have scores of 3.1 and 4.2, respectively. So, while Gyorko seems to have an advantage here, over the course of a 162-game season, this is a relatively insignificant difference.

Looking at Def, which measures the number of runs above or below average a player is worth, we see that Wong scores 8.2, while Gyorko scores 5.3. According to FanGraphs Rules of Thumb for interpreting this statistic, both players are between “above average” and “great defenders.” Wong’s advantage here equates to about 1/3 of a win. Again, no significant difference in their fielding abilities.

If we look at the Inside Edge Fielding statistics from FanGraphs, we see, as a whole, that Kolten makes more difficult plays, but Jedd makes the easier play a greater percentage of the time. For instance, look at the percentage of “unlikely” plays that each player made. An “unlikely” play is a play that is made 10-40% of the time. Kolten made 27% of these plays, while Jedd did not make a single one. At the same time, looking at plays that are “likely,” Kolten made 73% of them, while Jedd made significantly more (88%).

An analysis of these statistics shows us that, in the field, Kolten may make more web gems, but Jedd is the more consistent everyday second baseman. Nevertheless, there is not much separating these two on the defensive end.

At the Plate

At first, this part of the debate seems relatively simple. Gyorko led the team in HRs last year, he is clearly the much better hitter, right? Let’s take a look. At first glance, the players look very similar, with Jedd posting a line of .245/.301/.445 and Kolten producing a line of .254/.323/.375.

One key aspect of a platoon is starting the right-handed hitter against southpaws and vice versa. So let’s look at the zone profiles.

Kolten vs. Righties

Jedd vs. Lefties

Kolten is, far and away, the better hitter in this platoon in terms of average. But Gyorko’s greatest success was his power, right? So let’s look at the slugging zones.

Kolten slugging vs. Righties

Jedd slugging vs. Lefties

Although there are places where Jedd has the higher slugging percentage, Kolten has slightly lower, but similar zone ratings over a longer period of time. Even with advanced statistics, these two players are very difficult to separate.

By the eye test, Kolten seems to have the advantage in the field, but the statistics tell us that these two players are actually very similar. In addition, Jedd seems like the better hitter, but the statistics tell us that, again, they are very similar. Perhaps there is one thing that we can glean from this analysis: Kolten should be put in a place where he can reach base in front of players who drive the ball and Jedd should be placed where he can drive runners in.

To respond to the question asked at the beginning, should this platoon continue? The statistics tell us yes. As a younger player who just signed a large extension, Kolten has more upside. However, if we are to make a decision for this year, not the future, the numbers tell us that the platoon should continue because neither player has separated himself from the other.