Last week during his Twitter takeover, Astros GM Jeff Luhnow made reference to a Hardball Times article that spoke highly of George Springer, but in only 140 characters Luhnow declined to elaborate. Intrigued, the dedicated researchers at The Crawfish Boxes spent twenty seconds to Google the article to see what was so great that it was worth mention by the GM.
Our labors uncovered this: on October 15, Chris Mitchell of The Hardball Times published an article titled Improvements in Plate Discipline: Rare but Effective. The posting expanded upon previous research by Russell Carlton, Derek Carty, and Neil Paine that uses a batter's in-zone and out-of-zone swing rates as a proxy for plate discipline. What Mitchell found is that a player's plate discipline, as measured using the method described in those gentlemen's work, should not be expected to vary greatly over time. This is good news for players with good discipline. Not so much with those who don't have it.
A small caveat exists, as is the case with all statistical analysis that is relatively simplified. This method very slightly penalizes those players who don't swing at "bad pitches" in the zone, but it also boosts those players slightly who do swing at "bad pitches" in the zone. But the method (which is explained amply in the articles linked to Mitchell's, which you are encouraged to explore, is generally accepted as a useful estimation of a player's ability to make good decisions on which pitches to swing at.
What Luhnow referred to though, was that George Springer scored as the #1 batter in the majors (250+ plate appearances) in making the correct swing decision. Dexter Fowler ranked seventh. And since Mitchell's research shows that this particular metric fluctuates little over a player's career, an Astros fan can reasonably expect Springer and Folwer to continue being top performers in the selectivity department. When fivethirtyeight.com performed the same analysis, Fowler ranked #1 in baseball over the span from 2012 to April 2014 (4,300 pitches seen).
Duplicating this, and using 400 pitches seen as my floor (so that Jake Marisnick would be included in my list), here are the 2014 Houston Astros ranked by their ability to make good decisions. Their rankings are compared to all MLB players.
This table almost defies explanation. Out of over two hundred major leaguers who saw 400 or more pitches during 2014, four of the top 25 are everyday players for the Astros. Three regulars (if one includes Corp as a regular, which is fair) reside in the top 10.
Note that a low plate discipline score doesn't necessarily equate with offensive futility, and vice-versa. Jose Altuve, for example, built an MVP-discussion-worthy season by swinging at everything, and making contact with everything. If a player has elite bat control and contact skills, he can find success. Likewise, a player with exceptionally poor contact abilities (Springer) can succeed if they have elite-level plate discipline. By-and-large though, the best Astros hitters are near the top, and the worst are near the bottom.
- Astros fans should be encouraged about Jon Singleton because of this chart. By the measure of making correct swing decisions, he ranked 17th in all of baseball. As his batting profile is very similar to Springer's (all-or-nothing), this might indicate that the lion's share of his issues at the plate could have been caused by that ridiculously low .238 BABIP. He still struggles with making contact in the zone , but his contact rates are actually better than Springer's, and so a correction in BABIP should make his 2015 results lightyears better than in 2014.
- This bodes well for Marisnick as an option for "everyday outfielder". He already displays elite-level defense, and now we see that he is in the 90th percentile among MLB'ers at choosing whether or not to swing at pitches. Unlike Springer and Singleton though, he has a top-notch Z-Contact% and great wheels. If he can hit for a bit more pop (his career MiLB ISO is almost 100 points higher than his MLB ISO) and strike out a bit less (his MiLB K% is about 10 points lower than his MLB K%), he has the makings of an above-average batter.
- George Springer. My goodness.
- Judging from this, if Jason Castro can get his walk rate back up to it's pre-2014 level and his K-rate down closer to where it was in the minors, he could return to being an above-average batter as well, which considering his excellent defense, would be quite a coup for the Astros.
- Max Stassi is a great prospect, but Carlos Corporan keeps sneaking his way onto lists of positives for the Astros. With his top-flight defense, plate discipline, and pop, Corp looks like a guy who could easily start on some teams.
- Marwin Gonzalez is an oddity. His contact rate on pitches in the zone is approaching Altuve territory - his Z-Contact% is 91%, among the best in baseball. For comparison, Springer's is 68%, among the worst. In fact, Marwin's plate discipline stats mirror Altuve's across-the-board. Here we see how why players are able to overcome poor plate discipline (Altuve) or not (Marwin) -- it lies in the player's speed. Marwin has a 5% infield hit percentage on balls in play, and Altuve's is almost 11%. To be an above-average offensive player, even with his contact abilities, Marwin will need to come into some power or get some good luck on balls in play, as he did in 2014, because he doesn't have the speed to overcome his poor selectivity at the plate.
- Matt Dominguez was a mess in 2014. This data actually is disheartening because with good plate discipline, he might be able to overcome some of the issues that plagued him. But Mitchell shows that a player is unlikely to change his swing habits significantly. As I stated a couple weeks ago, Dominguez' best hope still seems to be in simplifying his swing to improve his bat speed and contact rate.